Posts tagged ‘Inconvenient Truth’

Stupid Math Tricks

James Hansen, head of NASA's GISS and technical adviser on An Inconvenient Truth, wrote recently


This statement alone should be enough for any thoughtful person who here-to-fore has bought in to global warming hysteria out of vague respect for "science" to question their beliefs.

First, he is basically arguing that a 3σ event proves (makes it "nearly certain") that some shift has occurred in the underlying process.  In particular, he is arguing that one single sample's value is due to a mean shift in the system.  I don't have a ton of experience in process control and quality, but my gut feel is that a 3σ event can be just that, a 3σ event.  One should expect a 3σ event to occur, on average, once in every 300 samples of a system with a normal distribution of outcomes.

Second, and a much bigger problem, is that Hansen is gaming the sampling process.  First, he is picking an isolated period.  Let's say, to be generous, that this 3σ event stretched over 3 months and was unprecedented in the last century.  But there are 400 3-month periods in the last hundred years.  So he is saying in these two locations there was a 3σ temperature excursion once out of 400 samples.  Uh, ok.  Pretty much what one would expect.

Or, if you don't like the historic approach, lets focus on just this year.  He treats Moscow and Texas like they are the only places being sampled, but in fact they are two of hundreds or even thousands of places on Earth.  Since he does not focus on any of the others, we can assume these are the only two that have so-called 3σ temperature events this summer.

It's hard to know how large to define "Texas"  (since the high temperatures did not cover the whole state) or "Moscow" (since clearly the high temperatures likely reached beyond the suburbs of just that city).

Let's say that the 3σ event occurred in a circular area 500km in diameter.  That is an area of 196,250 sq km each.  But the land surface area of the Earth (we will leave out the oceans for now since heat waves there don't tend to make the headlines) is about 150 million sq km.   This means that each of these areas represent about 1/764th of the land surface area of the Earth.  Or said another way, this summer there were 764 500km diameter land areas we could sample, and 2 had 3σ events.  Again, exactly as expected.

In other words, Hansen's that something unusual is going on in the system is that he found two 3σ events that happened once every 300 or 400 samples.  You feeling better about the science yet?

Luboš Motl has a more sophisticated discussion of the same statement, and gets into other issues with Hansen's statement.

Postscript:  One other issue -- the mean shift in temperatures over the last 30 years has been, at most, about 0.5C  (a small number compared to the Moscow temperature excursion from the norm).  Applying that new mean and the historic standard deviation, my guess is that the Moscow event would have still been a 2.5σ event.  So its not clear how an event that would have been unlikely even with global warming but slightly more unlikely without global warming tells us much of anything about changes in the underlying system, or how Hansen could possible assign blame for the even with near certainty to anthropogenic CO2.

CO2 and Tornadoes

Well, you now have a simple algorithm for sorting flakes and politicized hacks from honest scientists -- anyone who is going around this week saying that the tornadoes in Alabama this week were due to manmade CO2 sit firmly in the former category.  First up, Dr. Roy Spencer

If there is one weather phenomenon global warming theory does NOT predict more of, it would be severe thunderstorms and tornadoes.

Tornadic thunderstorms do not require tropical-type warmth. In fact, tornadoes are almost unheard of in the tropics, despite frequent thunderstorm activity.

Instead, tornadoes require strong wind shear (wind speed and direction changing rapidly with height in the lower atmosphere), the kind which develops when cold and warm air masses “collide”. Of course, other elements must be present, such as an unstable airmass and sufficient low-level humidity, but wind shear is the key. Strong warm advection (warm air riding up and over the cooler air mass, which is also what causes the strong wind shear) in advance of a low pressure area riding along the boundary between the two air masses is where these storms form.

But contrasting air mass temperatures is the key. Active tornado seasons in the U.S. are almost always due to unusually COOL air persisting over the Midwest and Ohio Valley longer than it normally does as we transition into spring.

For example, the poster child for active tornado seasons was the Superoutbreak of 1974, which was during globally cool conditions. This year, we are seeing much cooler than normal conditions through the corn belt, even delaying the planting schedule. Cool La Nina years seem to favor more tornadoes, and we are now coming out of a persistent La Nina. The global-average temperature has plummeted by about 1 deg. F in just one year.

An unusually warm Gulf of Mexico of 1 or 2 degrees right now cannot explain the increase in contrast between warm and cold air masses which is key for tornado formation because that slight warmth cannot compete with the 10 to 20 degree below-normal air in the Midwest and Ohio Valley which has not wanted to give way to spring yet.

The “extra moisture” from the Gulf is not that important, because it’s almost always available this time of year…it’s the wind shear that caused this outbreak.

More tornadoes due to “global warming”, if such a thing happened, would be more tornadoes in Canada, where they don’t usually occur. NOT in Alabama.

Thus we yet again run into the logic of the marketing campaign to change the effect of CO2 from global warming to climate change, as if CO2 could somehow make for random climate changes without the intermediate step of warming.

We all draw upon fallible memories to come to conclusions about whether events are more or less prevalent today, and in many cases our memories fail us (often due to observer bias, in particular the increasing frequency of an event in the media being mistaken for the increasing underlying frequency of the event).  I will say that my memory is that the seventies were the time in my life with the most severe weather (including horrible regional famines) and the seventies were the coldest decade of my life so far.

Anyway, tornadoes are something we can measure, rather than just remember, so let's go to the data:

In An Inconvenient Truth, Al Gore and company said that global warming was increasing the number of tornadoes in the US.  He claimed 2004 was the highest year ever for tornadoes in the US.  In his PowerPoint slide deck (on which the movie was based) he sometimes uses this chart (form the NOAA):

Whoa, that’s scary.  Any moron can see there is a trend there.  Its like a silver bullet against skeptics or something.  But wait.  Hasn’t tornado detection technology changed over the last 50 years?  Today, we have doppler radar, so we can detect even smaller size 1 tornadoes, even if no one on the ground actually spots them (which happens fairly often).  But how did they measure smaller tornadoes in 1955 if no one spotted them?  Answer:  They didn’t.  In effect, this graph is measuring apples and oranges.  It is measuring all the tornadoes we spotted by human eye in 1955 with all the tornadoes we spotted with doppler radar in 2000.   The NOAA tries to make this problem clear on their web site.

With increased national doppler radar coverage, increasing population, and greater attention to tornado reporting, there has been an increase in the number of tornado reports over the past several decades. This can create a misleading appearance of an increasing trend in tornado frequency. To better understand the true variability and trend in tornado frequency in the US, the total number of strong to violent tornadoes (F3 to F5 category on the Fujita scale) can be analyzed. These are the tornadoes that would have likely been reported even during the decades before Dopplar radar use became widespread and practices resulted in increasingtornado reports. The bar chart below indicates there has been little trend in the strongest tornadoes over the past 55 years.

So itt turns out there is a decent way to correct for this.  We don’t think that folks in 1955 were missing many of the larger class 3-5 tornadoes, so comparing 1955 and 2000 data for these larger tornadoes should be more apples to apples (via NOAA).

Well, that certainly is different (note 2004 in particular, given the movie claim).  No upward trend at all when you get the data right.  I wonder if Al Gore knows this?  I am sure he is anxious to set the record straight.

The last chart is dated - am I hiding something?  Nope, here is the update (from here)

By the way, note the 2nd to last bar, which I believe it the 2008 bar (this chart is really hard to read, but it is the only way I have found the data from the NOAA).  In spring of 2008, the media went nuts with a spring spate of tornadoes, saying that the apocalypse was here and this was the ultimate proof of global warming.  In particular, ABC ran a story about how the frequency was twice the previous year.  Beyond the insanity of drawing long term trends in a noisy system from 2 data points, notice that the previous year was virtually the lowest number in half a century, and despite being twice as high, 2008 turned out to be an average to lower-than-average tornado year.  This is what the media does with the climate issue, and why you can trust almost none of it.

Update: By the way, 10 of the top 10 deadliest tornadoes occurred before 1955?  An artifact of increasing wealth, better construction, and in particular better warning and communication systems?  Likely -- it is no accident, I think, these all occurred before the popularization of TV.  However, remember this argument when you see charts of increasing property damage from hurricanes.  These are also an artifact of increasing wealth, but the other way around -- more rich people build expensive houses on the beech, the more property damage from hurricanes irregardless of hurricane strength or frequency.

Update#2:  The entire outbreak may be the third deadliest in the century.

Analysis of "New" UN Climate Warming

mounting pressure from climate catastrophists to ignore uncertainties
in the science and to produce definitive statements that can be used as
calls for government interventionism, the UN will apparently release a new "warning" this week:

warming is destroying species, raising sea levels and threatening
say in a report today that U.N. officials hope will help mobilize the
world to take tougher actions on climate change.

The report
argues that only firm action, including putting a price on
carbon-dioxide emissions, will avoid more catastrophic events.

actions will take a small part of the world's economic growth and will
be substantially less than the costs of doing nothing, the report says.

For the first time, the UN is trying to
argue explicitly that the cost of CO2 abatement is lower than the cost
of doing nothing.  They are arguing that a cooler but poorer world is
superior to a warmer and richer world.  I am glad they are finally
arguing this point.  Because while we can argue about the truth of how
much the world has warmed and how much is due to man, the UN is DEAD
WRONG on this point.  The cost of aggressive CO2 abatement is far, far
higher than the cost of doing nothing.

The report presumably will be released by UN Secretary-General Ban Ki Moon, who demonstrated his stunning ignorance of climate science, geology, and geography on a recent climate-junket to Antarctica.  Let's take it line by line.

Is man destroying or threatening species?  Absolutely.  Is this threat from CO2 and warming? No, and I have read every inch of the UN IPCC report and you can find no evidence for this proposition.
But saying this rallies the environmental base (the hard core
environmentalists don't really care about poor people, at least when
their interests conflict with animals).  Most of the evidence is that
species thrive in warmer weather, and polar bears have survived several
inter-glaciation periods where the north pole melted entirely in the

Are sea levels rising?  Yes.  In fact, they have been
rising for at least 150 years, and in fact have been rising steadily
and at roughly the same rate since the last ice age.  We have seen
absolutely no acceleration of the underlying sea level rise trend.
Further, the UN's IPCC does have a forecast for sea level rise over the
next century.  Even using temperature forecasts I consider exaggerated,
the UN does not forecast more than about a foot of sea level rise over
the coming century, only a bit more than what the sea level has risen
over the last 150 years.  This is a great example of the disconnect
between the UN political climate reports and the science underlying
them.  The guys writing the summary know that their report says only a
few inches of sea level rise, so they just say it is rising, and then
let the crazies like Al Gore throw around numbers like 20 feet.

Here is an interesting thought:  If I say the sea levels
will rise 0" over the next 100 years, the UN will call me out and say I
am wrong.  However, when Al Gore said sea levels will rise 20 feet in
his movie An Inconvenient Truth, no one at the UN or the IPCC
called him out, despite the fact that my forecast was only a few inches off from theirs and his was 19 feet off the mark.

And of course, there are the poor.  The number one biggest
losers in any effort to abate CO2 emissions will be the poor.  In
wealthy countries like the US, the poor will be the hardest hit by $10
or even $20 gas prices that would be necessary to rolling CO2
production back to 1990 levels.  In the third world, nearly a billion
people just starting to emerge from poverty will have no chance of doing so if their economies are hamstrung with CO2 limits.  The poor will be devastated by aggressive CO2 limits.

Weighed against this economic disaster would be, what?
How would rising world temperatures hurt the poor?  Well, its not at
all clear.  A foot of sea-level rise is very unlikely to hurt many poor
people, though it might inconvenience a few rich owners of beach-front
luxury homes.  Here is a clarifying question I often ask people --
would you rather fifteen Atlantic hurricanes each year, or sixteen
hurricanes each year and Carribbean economies that are twice as rich
and therefore have twice the resources to handle hurricanes.  This is
the colder and poorer vs. warmer and richer choice.  We see this in Bangladesh today.  Why do orders of magnitude more people die in Bangladesh cyclones than class 5 hurricanes on the US shore?  Because they are poor, not because of anything having to do with global warming.

It is often claimed that global warming will cause
droughts, but in fact warmer world temperatures will vaporize more
water in the atmosphere and should net increase rain, not drought.  And
many of the farmers in the northern hemisphere would enjoy longer
growing seasons and thereby more food production.

shifting their range to accommodate warmer air and water; and planting
seasons are changing, the report said.

Yes, land-based ice is melting in the Northern Hemisphere.  This is 15% of the world's ice.  85% of the world's ice is in Antarctica, which is increasing.
Seriously.  I know you don't believe this if you trust the media, but
the ice that is melting in Greenland is tiny compared to the ice that
is increasing at the South Pole.  In fact, the IPCC gets most of its
prjected sea rise from thermal expansion of warmer oceans, not from ice
melting.  And don't you love the "planting seasons are changing."  That
sounds like its scary, or something, until you recognize the truth is
that planting seasons are changing, becoming longer and more beneficial to food production!

On many occasions, I have discussed the bad science that
goes into these apocalyptic forecasts.  But that science is of top
quality compared to the economics that must have gone into the
statement that:

The most
stringent efforts to stabilize greenhouse gases would cost the world's
economies 0.12 percent of their average annual growth to 2050, the
report estimates.

This is absolute, unmitigated crap.
Though I have not seen specifics in this report, the UN's position has
generally been that emissions should be rolled back to 1990 levels (the
target embodied in the Kyoto treaty).  Such a target implies reductions
of more than 20% from where we are today and well over 50% from where
we will be in 2050.  These are enormous cuts that cannot be achieved
with current technology without massive reductions in economic growth.
The world economy is inextricably tied to the burning of fossil fuels.
And, unlike ancillary emissions like SO2, CO2 emissions cannot be
limited without actually reducing carbon combustion since it is
fundamental to the combustion chemistry.  Even supporters of
legislation such as the Bingaman-Specter bill admit that as much as a
trillion dollars will need to be spent to reduce global temperatures
about 0.13C.  And that is a trillion for the first tenth of a degree --
the law of diminishing returns means that each additional tenth will
cost more.

Lets look at history as our guide.  Most of the European
countries and Japan signed onto the Kyoto Treaty to reduce emissions to
1990 levels.  They have taken many expensive steps to do so,
implemented many more controls than in the US, and have gas prices as
much as double those in the US.  During the period since 1990, most of
these countries, unlike the US and China and India, have been in a deep
and extended economic recession, which tends to suppress the growth of
fossil fuel consumption.  Also, the CO2 numbers for countries like
Russia and Germany benefit greatly from the fall of the old Communist
Block, as their 1990 base year CO2 numbers include many horribly
inefficient and polluting Soviet industries that have since been shut
down.  And, given all this, they STILL are going to miss
their numbers.  These countries have experienced reductions in economic
growth orders of magnitude greater than this 0.12 percent quoted by the
UN, and that still is not enough to reduce CO2 to target levels.  Only
outright contraction of the world's economy is going to suffice [note:
A strong commitment to replacing coal plants with nuclear might be a
partial solution, but it will never happen because the people calling
for CO2 controls are the same ones who shut down our nuclear programs.
Also, technological change is always possible.  It would be awesome if
someone found a way to roll out sheets of efficient solar cells like
carpet out of Dalton, Georgia, but that has not happened yet.]

The UN has gotten to such low cost estimates for their
government controls because they have convinced themselves, much like
the promoters of building football stadiums for billionaire team
owners, that they will get a huge return from the government CO2

"There is high
agreement and much evidence that mitigation actions can result in
said the report, which summarizes research over five years of more than
2,000 of the world's top climate-change scientists...

The U.N. panel embraced the arguments of British economist
measures to curb pollution will be repaid in the long run.

Stern?  Haven't we heard that name before?  Why, yes we have.  He is
the man that said that all of the world's climate problems would go
away if we forced all the western economies to look just like India.

Stern, the former chief economist of the World Bank, sends out a very
clear message: "We need to cut down the total amount of carbon
emissions by half by 2050." At current levels, the per capita global
emissions stand at 7 tonnes, or a total of 40-45 gigatonnes. At this
rate, global temperatures could rise by 2.5-3 degrees by then. But to
reduce the per capita emissions by half in 2050, most countries would
have to be carbon neutral. For instance, the US currently has, at 20-25
tonnes, per capita emissions levels that are three times the global

The European Union's emission levels stand at 10-15
tonnes per capita. China is at about 3-4 tonnes per capita and India,
at 1 tonne per capita, is the only large-sized economy that is below
the desired carbon emission levels of 2050. "India should keep it that way and insist that the rich countries pay their share of the burden in reducing emissions," says Mr Stern.

by the way, is exactly my point.  I very much hope Mr. Stern continues
to make this clear in public.  One of the ways catastrophists support
their cause of massive government interventionism is to try to portray
the answer as little cutsie actions, like your 5-year-old helping with
the recycling
.  This is not what is require to meet these targets.
What is required is ratchet down the US economy until we are all about
as wealthy as the average Indian.  I guess that would at least take
care of the outsourcing "problem."

One of the ways that the UN gets away with this is that no
one has the time to read the detailed scientific report, and so
reporters rely on the summaries like these.  Unfortunately, the same
people who write the scientific sections are not the people who write
the summaries.  Careful language about uncertainties, which are still
huge, in the science are replaced by summaries written by politicians
that say:

The near-final draft,
approved Friday by representatives of more than 140 governments meeting
in Valencia, Spain, said global warming is "unequivocal" and said man's
actions are heading toward "abrupt or irreversible climate changes and

the blueprint for the Bali talks," said Sen. John Kerry, D-Mass., who
U.S. senatorial delegation.

technique used by the UN that we see in play here is their willingness
to cherry-pick one author that follows the UN narrative to refute a
whole body of science that is contrary to the narrative.  Thus, the UN
latched onto Michael Mann's hockey stick to overturn a consensus that
there was a Medieval warm period, and now they have latched onto
Nicholas Stern to overturn the opinion of, approximately, every other
economist in the world who think CO2 mitigation will be really

As always, you are encourage to view my movie What is Normal:  A Critique of Catastrophic Man-Made Global Warming Theory or check out my book (free online) called A Skeptical Layman's Guide to Anthropogenic Global Warming.

By the way, in the title I put "new" in quotes.  Here is why.  I just read a presentation by Dr. Richard Lindzen from 1992 that shows that catastrophists were declaring the debate "over" as early as 1989, before any real research had even been performed:

By early 1989, however, the popular media in Europe and the United States were declaring that "all scientists'' agreed that warming was real and catastrophic in its potential.
In the meantime, the global warming circus was in
full swing. Meetings were going on nonstop. One of the more striking of
those meetings was hosted in the summer of 1989 by Robert Redford at
his ranch in Sundance, Utah. Redford proclaimed that it was time to stop research and begin acting.
I suppose that that was a reasonable suggestion for an actor to make,
but it is also indicative of the overall attitude toward science.
Barbara Streisand personally undertook to support the research of
Michael Oppenheimer at the Environmental Defense Fund, although he is
primarily an advocate and not a climatologist. Meryl Streep made an
appeal on public television to stop warming. A bill was even prepared
to guarantee Americans a stable climate

Reality Checking Global Warming Forecasts

I know I have deluged you with a lot of climate change posts of late.  I think this particular post is important, as it is the clearest single argument I can make as to why I am skeptical that man-made global warming will rise to catastrophic levels.  It is not comprehensive, it took me 80 pages to do that, but it should get anyone thinking.

It turns out to be quite easy to do a simple but fairly robust reality check of global warming forecasts, even without knowing what a "Watt" or a "forcing" is.   Our approach will be entirely empirical, based on the last 100 years of climate history.  I am sensitive that we skeptics not fall into the
9/11 Truther syndrome of arguing against a coherent theory from
isolated anomalies
.  To this end, my approach here is holistic and not
anomaly driven.  What we
will find is that, extrapolating from history, it is almost impossible to get warming numbers as high as those quoted by global warming alarmists.

Climate Sensitivity

The one simple concept you need to understand is "climate sensitivity."  As used in most global warming literature, climate sensitivity is the amount of global warming that results from a doubling in atmospheric CO2 concentrations.   Usually, when this number is presented, it refers to the warming from a doubling of CO2 concentrations since the beginning of the industrial revolution.  The pre-industrial concentration is generally accepted as 280ppm (0.028% of the atmosphere) and the number today is about 380ppm, so a doubling would be to 560ppm.

As a useful, though not required, first step before we begin, I encourage you to read the RealClimate simple "proof" for laymen that the climate sensitivity is 3ºC, meaning the world will warm 3 degrees C with a doubling of CO2 concentrations from their pre-industrial level.  Don't worry if you don't understand the whole description, we are going to do it a different, and I think more compelling, way (climate scientists are a bit like the Wizard of Oz -- they are afraid if they make things too simple someone might doubt they are a real wizard).  3ºC is a common number for sensitivity used by global warming hawks, though it is actually at the low end of the range that the UN IPCC arrived at in their fourth report.  The IPCC (4th report, page 798) said that the expected value is between 3ºC and 4ºC and that there was a greater chance the sensitivity was larger than 6ºC than that it was 1.5ºC or less.  I will show you why I think it is extraordinarily unlikely that the number is greater even than 1.5ºC.

Our Approach

We are going to derive the sensitivity (actually a reasonable range for sensitivity) for ourselves in three steps.  First, we will do it a simple way.  Then, we will do it a slightly harder but more accurate way.  And third, we will see what we would have to assume to get a number anywhere near 3ºC.  Our approach will be entirely empirical, using past changes in CO2 and temperature to estimate sensitivity.  After all, we have measured CO2 going up by about 100 ppm.  That is about 36% of the way towards a doubling from 280 to 560.  And, we have measured temperatures -- and though there are a lot of biases in these temperature measurements, these measurements certainly are better than our guesses, say, of temperatures in the last ice age.  Did you notice something odd, by the way, in the RealClimate derivation?  They never mentioned measured sensitivities in the last 100 years -- they jumped all the way back to the last ice age.  I wonder if there is a reason for that?

A First Approximation

OK, let's do the obvious.  If we have experienced 36% of a doubling, then we should be able to take the historic temperature rise from CO2 for the same period and multiply it by 2.8 (that's just reciprocal of 36%) and derive the temperature increase we would expect for a full doubling.

The problem is that we don't know the historic temperature rise solely form CO2.  But we do know how to bound it.  The IPCC and most global warming hawks place the warming since 1900 at about 0.6ºC.  Since no one attributes warming before 1900 to man-made CO2  (it did warm, but this is attributed to natural cyclical recovery from the little ice age) then the maximum historic man-made warming is 0.6ºC.  In fact, all of that warming is probably not from CO2.  Some probably is from continued cyclical warming out of the little ice age.  Some, I believe strongly, is due to still uncorrected biases, particularly of urban heat islands, in surface temperature data. 

But let's for a moment attribute, unrealistically, all of this 0.6ºC to man-made CO2 (this is in fact what the IPCC does in their report).   This should place an upper bound on the sensitivity number.  Taking 0.6ºC times 2.8 yields an estimated  climate sensitivity of  1.7ºC.  Oops.  This is about half of the RealClimate number or the IPCC number! And if we take a more realistic number for man-made historic warming as 0.4ºC, then we get a sensitivity of 1.1ºC.  Wow, that's a lot lower! We must be missing something important!  It turns out that we are, in this simple analysis, missing something important.  But taking it into account is going to push our sensitivity number even lower.

A Better Approximation

What we are missing is that the relation between CO2 concentration and warming is not linear, as implied in our first approximation.  It is a diminishing return.  This means that the first 50 ppm rise in CO2 concentrations causes more warming than the next 50 ppm, etc.  This effect has often been compared to painting a window.  The first coat of paint blocks out a lot of light, but the window is still translucent.  The next coat blocks out more light, but not as much as the first.  Eventually, subsequent coats have no effect because all the light is already blocked.  CO2 has a similar effect on warming.  It only absorbs certain wavelengths of radiation returning to space from earth.  Once the absorption of those wavelengths is saturated, extra CO2 will do almost nothing. (update:  By the way, this is not some skeptic's fantasy -- everyone in climate accepts this fact).

So what does this mean in English?  Well, in our first approximation, we assumed that 36% of a CO2 doubling would yield 36% of the temperature we would get in a doubling.  But in reality, since the relationship is a diminishing return, the first 36% of a CO2 doubling will yield MORE than 36% of the temperature increase you get for a doubling.  The temperature increase is front-loaded, and diminishes going forward.   An illustration is below, with the linear extrapolation in red and the more realistic decreasing exponential extrapolation in blue.


The exact shape and equation of this curve is not really known, but we can establish a reasonable range of potential values.  For any reasonable shapes of this curve, 36% of a CO2 doubling (where we are today) equates to from 43% to 63% of the final temperature increase over a doubling.  This would imply that a multiplier between 2.3 and 1.6 for temperature extrapolation  (vs. 2.8 derived above for the straight linear extrapolation above) or a climate sensitivity of 1.4ºC to 1.0ºC if man-made historic warming was 0.6ºC and a range of 0.9ºC to 0.6ºC for a man-made historic warming of 0.4ºC.  I tend to use the middle of this range, with a multiplier of about 1.9 and a man-made historic warming of 0.5ºC to give a expected sensitivity of 0.95ºC, which we can round to 1ºC. 

This is why you will often hear skeptics cite numbers closer to 1ºC rather than 3ºC for the climate sensitivity.   Any reasonable analysis of actual climate experience over the last 100 years yields a sensitivity much closer to 1ºC than 3ºC.  Most studies conducted before the current infatuation with showing cataclysmic warming forecasts came up with this same 1ºC, and peer-reviewed work is still coming up with this same number

So what does this mean for the future?  Well, to predict actual temperature increases from this sensitivity, we would have to first create a CO2 production forecast and, you guessed it, global warming hawks have exaggerated that as well.  The IPCC says we will hit the full doubling to 560ppm around 2065 (Al Gore, incredibly, says we will hit it in the next two decades).  This means that with about 0.5C behind us, and a 3 sensitivity, we can expect 2.5C more warming in the next 60 years.  Multiply that times exaggerated negative effects of warming, and you get instant crisis.

However, since actual CO2 production is already below IPCC forecasts, we might take a more reasonable date of 2080-2100 for a doubling to 560.  And, combining this with our derived sensitivity of 1ºC (rather than RealClimate's 3ºC) we will get 0.5C more warming in the next 75-100 years.  This is about the magnitude of warming we experienced in the last century, and most of us did not even notice.

I know you are scratching you head and wondering what trick I pulled to get numbers so much less than the scientific "consensus."  But there is no trick, all my numbers are empirical and right out of the IPCC reports.  In fact, due to measurement biases and other climate effects that drive warming, I actually think the historic warming from CO2 and thus the sensitivity is even lower, but I didn't want to confuse the message. 

So what are climate change hawks assuming that I have not included?  Well, it turns out they add on two things, neither of which has much empirical evidence behind it.  It is in fact the climate hawks, not the skeptics, that need to argue for a couple of anomalies to try to make their case.

Is Climate Dominated by Positive Feedback?

Many climate scientists argue that there are positive feedbacks in the climate system that tend to magnify and amplify the warming from CO2.  For example, a positive feedback might be that hotter climate melts sea ice and glaciers, which reduces the reflectiveness of the earth's surface, which causes more sunlight to be absorbed, which warms things further.  A negative feedback might be that warmer climate vaporizes more water which forms more clouds which blocks sunlight and cools the earth. 

Climate scientists who are strong proponents of catastrophic man-made warming theory assume that the climate is dominated by positive feedbacks.  In fact, my reading of the IPCC report says that the climate "consensus" is that net feedback in the climate system is positive and tends to add 2 more degrees of temperature for every one added from CO2.  You might be thinking - aha - I see how they got a sensitivity of 3ºC:  Your 1ºC plus 2ºC in feedback equals 3ºC. 

But there is a problem with that.  In fact, there are three problems with this.  Here they are:

  1. We came up with our 1ºC sensitivity empirically.  In other words, we observed a 100ppm past CO2 increase leading to 0.5ºC measured temperature increase which implies 1ºC sensitivity.  But since this is empirical, rather than developed from some set of forcings and computer models, then it should already be net of all feedbacks.  If there are positive feedbacks in the system, then they have been operating and should be part of that 1ºC.
  2. There is no good scientific evidence that there is a large net positive feedback loop in climate, or even that the feedback is net positive at all.  There are various studies, hypotheses, models, etc., but no proof at all.  In fact, you can guess this from our empirical data.  History implies that there can't be any large positive feedbacks in the system or else we would have observed higher temperatures historically.  In fact, we can go back in to the distant historical record (in fact, Al Gore showed the chart I am thinking of in An Inconvenient Truth) and find that temperatures have never run away or exhibited any sort of tipping point effect.
  3. The notion that a system like climate, which has been reasonably stable for millions of years, is dominated by positive feedback should offend the intuition of any scientist.  Nature is dominated in large part by negative feedback processes.  Positive feedback processes are highly unstable, and tend to run away to a distant endpoint.  Nuclear fission, for example, is a positive feedback process

Do aerosols and dimming imply a higher sensitivity?

Finally, the last argument that climate hawks would employ is that anthropogenic effects, specifically emission of SO2 aerosols and carbon black, have been reflecting sunlight and offsetting the global warming effect.  But, they caution, once we eliminate these pollutants, which we have done in the West (only to be offset in China and Asia) temperatures will no longer be suppressed and we will see the full extent of warming.

First, again, no one really has any clue the magnitude of this effect, or even if it is an effect at all.  Second, its reach will tend to be localized over industrial areas (since their presence in the atmosphere is relatively short-lived), whereas CO2 acts worldwide.  If these aerosols and carbon black are concentrated say over 20% of the land surface of the world, this means they are only affecting the temperature over 5% of the total earth' s surface.  So its hard to argue they are that significant.

However, let's say for a moment this effect does exist.  How large would it have to be to argue that a 3.0ºC climate sensitivity is justified by historical data?  Well, taking 3.0ºC and dividing by our derived extrapolation multiplier of 1.9, we get required historic warming due to man's efforts of 1.6ºC.  This means that even if all past 0.6ºC of warming is due to man (a stretch), then aerosols must be suppressing a full 1ºC of warming.   I can't say this is impossible, but it is highly unlikely and certainly absolutely no empirical evidence exists to support any number like this. Particularly since dimming effects probably are localized, you would need as much as 20ºC suppression in these local areas to get a 1ºC global effect.  Not very likely.

Why the number might even be less

Remember that when we calculated sensitivity, we needed the historical warming due to man's CO2.  A simple equation for arriving at this number is:

Warming due to Man's CO2 = Total Historic Measured Warming - Measurement Biases - Warming from other Sources + Warming suppressed by Aerosols

This is why most skeptics care if surface temperature measurements are biased upwards or if the sun is increasing in intensity.  Global warming advocates scoff and say that these effects don't undermine greenhouse gas theory.  And they don't.  I accept greenhouse gases cause some warming.  BUT, the more surface temperature measurements are biased upwards and the more warming is being driven by non-anthropogenic sources, the less that is being caused by man.  And, as you have seen in this post, the less warming caused by man historically means less that we will see in the future.  And while global warming hawks want to paint skeptics as "deniers", we skeptics want to argue the much more interesting question "Yes, but how much is the world warming, and does this amount of warming really justify the costs of abatement, which are enormous."


As always, you can find my Layman's Guide to Skepticism about Man-made Global Warming here.  It is available for free in HTML or pdf download, or you can order the printed book that I sell at cost.  My other recent posts about climate are here.

Storm Frequency

I already discussed Newsweek's happy little ad hominem attack on climate skeptics here.  However, as promised, I wanted to talk about the actual, you know, science for a bit, starting from the Newsweek author's throwaway statement that she felt required no
proof, "The frequency of Atlantic hurricanes has already doubled in the
last century."

This is really a very interesting topic, much more interesting than following $10,000 of skeptics' money around in a global warming industry spending billions on research.  One would think the answer to this hurricane question is simple.  Can we just look up the numbers?  Well, let's start there.  Total number of Atlantic hurricanes form the HURDAT data base, first and last half of the last century:

1905-1955 = 366
1956-2006 = 458

First, you can see nothing like a doubling.  This is an increase of 25%.  So already, we see that in an effort to discredit skeptics for fooling America about the facts, Newsweek threw out a whopper that absolutely no one in climate science, warming skeptic or true believer, would agree with.

But let's go further, because there is much more to the story.  Because 25% is a lot, and could be damning in and of itself.  But there are problems with this data.  If you think about storm tracking technology in 1905 vs. 2005, you might see the problem.  To make it really clear, I want to talk about tornadoes for a moment.


Whoa, that's scary.  Any moron can see there is a trend there.  Its like a silver bullet against skeptics or something.  But wait.  Hasn't tornado detection technology changed over the last 50 years?  Today, we have doppler radar, so we can detect even smaller size 1 tornadoes, even if no one on the ground actually spots them (which happens fairly often).  But how did they measure smaller tornadoes in 1955 if no one spotted them?  Answer:  They didn't.  In effect, this graph is measuring apples and oranges.  It is measuring all the tornadoes we spotted by human eye in 1955 with all the tornadoes we spotted with doppler radar in 2000.   The NOAA tries to make this problem clear on their web site.

With increased national doppler
radar coverage, increasing population, and greater attention to tornado
tornadoes that would have likely been reported even during the decades before
Dopplar radar use became widespread and practices resulted in increasing
tornado reports. The bar chart below indicates there has been little trend in
the strongest tornadoes over the past 55 years.

So itt turns out there is a decent way to correct for this.  We don't think that folks in 1955 were missing many of the larger class 3-5 tornadoes, so comparing 1955 and 2000 data for these larger tornadoes should be more apples to apples (via NOAA).


OK, back to hurricanes.  Generally, whether in 1905 or 2005, we know if a hurricane hits land in the US.  However, what about all the hurricanes that don't hit land or hit land in some undeveloped area?  Might it be that we can detect these better in 2006 with satellites than we could in 1905?  Just like the tornadoes?

Well, one metric we have is US landfall.  Here is that graph  (data form the National Weather Service -- I have just extrapolated the current decade based on the first several years).

Not much of a trend there, though the current decade is high, in part due to the fact that it does not incorporate the light 2006 season nor the light-so-far 2007 season.  The second half of the 20th century is actually lower than the first half, and certainly not "twice as large".  But again, this is only a proxy.  There may be reasons more storms are formed but don't make landfall (though I would argue most Americans only care about the latter).

But what about hurricane damages?  Everyone knows that the dollar damages from hurricanes is way up.  Well, yes.  But the amount of valuable real estate on the United State's coast is also way up.  Roger Pielke and Chris Landsea (you gotta love a guy studying hurricane strikes named Landsea) took a shot at correcting hurricane damages for inflation and the increased real estate value on the coasts.  This is what they got:

Anyway, back to our very first data, several scientists are trying to correct the data for missing storms, particularly in earlier periods.  There is an active debate here about corrections I won't get into, but suffice it to say the difference between the first half of the 20th century to the latter half in terms of Atlantic hurricane formations is probably either none or perhaps a percentage increase in the single digits (but nowhere near 100% increase as reported by Newsweek).

Debate continues, because there was a spike in hurricanes from 1995-2005 over the previous 20 years.  Is this anomalous, or is it similar to the spike that occurred in the thirties and forties?  No one is sure, but isn't this a lot more interesting than figuring out how the least funded side of a debate gets their money?  And by the way, congratulations again to MSM fact-checkers.

My layman's guide to skepticism of catastrophic man-made global warming is here.  A shorter, 60-second version of the best climate skeptic's arguments is here.

Update:  If the author bothered to have a source for her statement, it would probably be Holland and Webster, a recent study that pretty much everyone disagrees with and many think was sloppy.  And even they didn't say activity had doubled.  Note the only way to get a doubling is to cherry-pick a low decade in the first half of the century and a high decade in the last half of the century and compare just those two decades -- you can see this in third paragraph of the Scientific American article.  This study bears all the hallmarks -- cherry picking data, ignoring scientific consensus, massaging results to fit an agenda -- that the Newsweek authors were accusing skeptics of.

Update #2:  The best metric for hurricane activity is not strikes or numbers but accumulated cyclonic energy.  Here is the ACE trend, as measured by Florida State.  As you can see, no upward trend.


The 60-Second Climate Skeptic

I was trying to think about what I wanted to do for my last post in my recent orgy of global warming writing.  My original attempt to outline the state of the climate skeptic's case ballooned into 80+ pages, so there may be many people who rationally just have no desire to tackle that much material.  So I decided for this last post to try to select the one argument I would use if I had only 60 seconds to make the climate skeptic's case. But how do you boil down 80 pages to a few simple statements?

I'm not that interested in the Sun or cosmic rays -- they are interesting topics, but its dumb to try to argue we overestimate our understanding of man's impact on climate only to counter with topics we understand even less.  One of the reasons I wrote the paper in the first place was because I thought recent skeptical documentaries spent too much time on this subject.  And I would not get into tree rings or ice cores or other historic proxy data, though there is a lot happening in these areas.  I wouldn't even delve into the hysterical treatment of skeptics by man-made climate advocates  -- these are ad hominem issues that are useful to understand in a more comprehensive view but don't make for strong stand-alone arguments.

Anyway, here goes, in a logic chain of 8 steps.

  1. CO2 does indeed absorb reflected sunlight returning to space from earth, having a warming effect.  However, this effect is a diminishing return -- each successive increment of CO2 concentrations will have a much smaller effect on temperatures than the previous increment.  Eventually, CO2 becomes nearly saturated in its ability to absorb radiation.  The effect is much like painting a red room with white paint.  The first coat covers a lot of red but some still shows through.  Each additional coat will make the room progressively whiter, but each successive coat will have a less noticeable effects than the previous coat, until the room is just white and can't get any whiter.
  2. In the 20th century, the UN IPCC claims Earth's surface temperatures have increased by about a 0.6 degree Celsius (though there are some good reasons to think that biases in the installation of temperature instruments have exaggerated this apparent increase).  To be simple (and generous), let's assume all this 0.6C increase is due to man-made greenhouse gasses.  Some may in fact have been due to natural effects, but some may also have been masked by man-made sulfate aerosols, so lets just call man-made warming to be 0.6C. 
  3. Since the beginning of the industrial revolution, it is thought that man has increased atmospheric CO2 concentrations from 0.028% of the atmosphere to 0.038% of the atmosphere.  Since scientists often talk about the effect of a doubling of CO2, this historic rise in CO2 is 36% of a doubling.
  4. Using simple math, we see that if temperatures have risen 0.6C due to 36% of a doubling, we might expect them to rise by 1.67C for a full doubling to 0.056% of the atmosphere.  But this assumes that the rise is linear -- and we already said (and no one denies) that it is in fact a diminishing return relationship.  Using a truer form of the curve, a 0.6C historic rise for 36% of a doubling implies a full doubling would raise temperatures by about 1.2C, or about 0.6C more than we have seen to date (see chart below).   This means that the magnitude of global warming in the next century might be about what we have seen (and apparently survived) since 1900.
  5. Obviously, there is some kind of disconnect here.  The IPCC predicts temperature increases in the next century of 4-8 degrees C.  Big difference.  In fact, the IPCC predicts we will get a 0.5C rise in just 20 years, not 70-100.  Whereas we derived a climate sensitivity of 1.2 from empirical data, they arrive at numbers between 3 and 4 or even higher for sensitivity.  The chart below shows that to believe sensitivity is 3, we would have to have seen temperature rises due to man historically of 1.5C, which nobody believes. 

    So how do they get accelerating temperatures from what they admit to be a diminishing return relation between CO2 concentration and temperature? And for which there is no empirical evidence?  Answer:  Positive feedback.

  6. Almost every process you can think of in nature operates by negative
    feedback.  Roll a ball, and eventually friction and wind resistance bring
    it to a stop.  Negative feedback is a ball in the bottom of a bowl; positive feedback is a ball perched precariously at the time of a mountain. Positive feedback
    breeds instability, and processes that operate by positive feedback are
    dangerous, and usually end up in extreme states -- these processes tend to
    "run away" like the ball rolling down the hill.  Nuclear fission, for example, is a positive feedback process.  We should be happy there are not more positive feedback
    processes on our planet.  Current man-made global warming theory, however, asserts that our climate is dominated by positive feedback.  The IPCC posits that a small increase in temperature from CO2 is multiplied 2,3,4 times or more by positive feedbacks like humidity and ice albedo.
  7. There are three problems with these assumptions about positive feedback.  One, there is no empirical evidence at all that positive feedbacks in climate dominate negative feedbacks.   The 20th century temperature numbers we discussed above show no evidence of these feedbacks.  Two, the long-term temperature record demonstrates that positive feedbacks can't dominate, because past increases in temperature and CO2 have not run away.  And three, characterizations of stable natural processes as being dominated by positive feedback should offend the intuition and common sense of any scientist.
  8. An expected 21st century increase of 0.5 or even 1 degree C does not justify the massive imposed government interventions that will be costly both in dollars and lost freedoms.  In particular, the developing world will be far better off hotter by a degree and richer than it would be cooler and poorer.  This is particularly true since sources like an Inconvenient Truth wildly exaggerate the negative effects of global warming.  There is no evidence tornadoes or hurricanes or disease or extinction are increasing as the world warms, and man-made warming advocates generally ignore any potential positive effects of warming.  As to rising sea levels, the IPCC predicts only a foot and a half of sea level rise even with 4 or more degrees of warming.  Sea level rise from a half to one degree of warming would be measured at most in inches.

OK, so that was more than 60 seconds.  But it is a lot less than 80 pages.  There is a lot of complexity behind every one of these statements.  If you are intrigued, or at least before you accuse me of missing something critical, see my longer paper on global warming skepticism first, where all these issues and much more (yes, including tree rings and cosmic rays) are discussed in more depth.

Chapter 2: Is it OK to be a Skeptic? (Skeptics Guide to Global Warming)

The table of contents for the rest of this paper, . 4A Layman's Guide to Anthropogenic Global Warming (AGW) is here Free pdf of this Climate Skepticism paper is here and print version is sold at cost here

 For the first time since the Catholic Church
dominated western man's affairs, it has suddenly become a sin again to be
labeled a "skeptic."  For most of my lifetime, "skepticism" was considered
an essential element in the makeup of any good scientist (or journalist, for
that matter).   However, leading world figures are declaring
skepticism to be immoral.  Take one example, from this

A former chief of the U.N. World
Health Organization who also is a former prime minister of Norway and a medical
doctor has declared an end to the climate-change debate.

Dr. Gro Harlem Brundtland, one of U.N.
Secretary-General Ban Ki-moon's three new special envoys on climate change, also headed up the 1987 U.N. World
Commission on Environment and Development where the concept of sustainable
development was first floated.

"This discussion is behind us. It's
the issues."

In its most extreme form, this approach has AGW supporters
labeling skeptics as equivalent to "holocaust deniers" and "tobacco
lawyers."  Efforts have been made in several quarters to decertify
climatologists or meteorologists who show any skepticism for AGW theory, making
public adherence to the theory a minimum qualification for publication and
professional standing.  Enormous efforts are made to squelch skeptical
speech.  Just as one example, the BBC has run a zillion shows and specials
sympathetic to AGW.  When Channel 4 ran one single show (called the
"Global Warming Swindle") which outlined parts of the skeptics' position, 37 scientists attempted to have it
suppressed by the government

This is all the more incredible given that AGW theory has
only really been researched seriously and with any critical mass for about 20
years.  Anyone who has studied the history of science will understand what
incredible hubris it is to declare any new scientific theory, particularly one
that concerns the unbelievably chaotic climate, as "done" after just 20 years

Let me give two quick examples of just how unsettled the
science of climate change is.  Both of these will be reviewed in more
depth later in this paper, and both analyses figured prominently in the third
IPCC report (2001) as well as Al Gore's An Inconvenient Truth.  The
first is a 100,000 year temperature and CO2-level reconstruction from ice-core
data.  Anyone who saw Gore's movie will remember the data in one of his
Really Big Charts.  And it looks compelling "“ in fact, when I first saw
the chart five years ago, it was compelling to me.  It shows CO2 levels
and temperature moving in lock-step for 100,000 years.  When CO2 is up,
temperature is up and vice-versa, the clear implication being that CO2 seems to
be a key, maybe the key, driver of climate   However, since
that chart was first prepared, laboratory procedure has improved, and
scientists have found (and there is very little disagreement about this, even
among strong AGW supporters) that temperature increases occur on average 800
years before the CO2 starts to increase.  Huh.  There is a lot
of debate about what this means, but in the last five years, this formerly definitive
analysis is clearly no longer definitive, since it is hard to cause something
after the fact.

The other example is the very famous Mann hockey stick
chart, prominently featured in Gore's movie and a key part of the IPCC report
in 2001.  I will go into the details later, but since 2001 this analysis
has been effectively discredited, so much so it was almost entirely missing
from the fourth IPCC report in 2007.  In 2003 or so, Al Gore and many AGW
supporters would have called the Mann hockey stick chart the single most
important analysis "proving" AGW, and Gore treated it as such in his PowerPoint
deck and his movie.  Then, in 2007, it is repudiated and expunged from the
record.  Is this really what any reasonable person would call a "settled"

It is a true perversion of the scientific process to find
that skepticism is no longer welcome or accepted in scientific debate.
Which is one reason that AGW is sometimes called a secular religion.
Because it is religion, not science, that burns skeptics at the stake.  Climate
Scientists Garth Paltridge wrote

A colleague of mine put it rather
well. The IPCC, he said, has developed a highly successful immune system. Its
climate scientists have become the equivalent of white blood cells which rush
in overwhelming numbers to repel infection by ideas and results which do not
support the basic thesis that global warming is perhaps the greatest of the
modern threats to mankind.

Charges of Bias

A funny thing has happened in climate science to scientific inquiry:
the usual ethics of free discussion and fact-based criticism have been
discarded in favor of ad hominem attacks on critics of AGW theory.
The usual approach is to find some connection (even an imagined one) between
any researcher who raises the smallest doubts about AGW theory and an oil or
power company and then declare that the research is tainted by the bias of
these companies that have a strong economic reliance on fossil fuel combustion
(and thus the production of CO2).  A good example can be found in a Boston
Globe article
on MIT's Alfred P. Sloan professor of meteorology Richard
Lindzen.  Mr. Lindzen has become the bete noir of AGW supporters,
since his skepticism is harder to dismiss given his scientific pedigree and his
co-lead author status on the first IPCC climate change report.

"We do not understand the natural internal
variability of climate change" is one of Lindzen's many heresies, along
with such zingers as `"the Arctic was as warm or warmer in 1940,"
"the evidence so far suggests that the Greenland ice sheet is actually
growing on average," and "Alpine glaciers have been retreating since
advancing again. And, frankly, we don't know why."

When Lindzen published similar views in The Wall
Street Journal this spring, environmentalist Laurie David, the wife of comedian
Larry David, immediately branded him a "shill." She resurrected a
shopworn slur first directed against Lindzen by former Globe writer Ross
Gelbspan, who called Lindzen a "hood ornament" for the fossil fuels
industry in a 1995 article in Harper's Magazine....

For no apparent reason, the state of California,
Environmental Defense, and the Natural Resources Defense Council have dragged
Lindzen and about 15 other global- warming skeptics into a lawsuit over auto-
emissions standards. California et al. have asked the auto companies to cough
up any and all communications they have had with Lindzen and his colleagues,
whose research has been cited in court documents.

"We know that General Motors has been paying
for this fake science exactly as the tobacco companies did," says ED
attorney Jim Marston. If Marston has a scintilla of evidence that Lindzen has
been trafficking in fake science, he should present it to the MIT provost's
office. Otherwise, he should shut up.

"This is the criminalization of opposition to
global warming," says Lindzen, who adds he has never communicated with the
auto companies involved in the lawsuit.

While I have no doubt that corporations are heavily
influenced by their own economic interests, it is more of stretch to argue that
anyone who has ever taken money from them or had any connection with them would
purposely bias their research.  When I learned to debate, I was taught
that understanding biases was useful in knowing when to apply more or less
skepticism, but one still has to refute the opposing position by meaningful
critique of procedures or data.   For example, one might say "given
their strong desire to buttress the case for AGW, the researchers cherry-picked
only the most extreme data, which I will demonstrate by showing the data they
included and the data they chose to exclude."  However, many modern AGW
supporters believe that insinuating possible sources of bias is sufficient to
exempt one from having to actually critique their opponents' methods and

This is particularly odd given that public funding for AGW
projects absolutely dwarfs any funding coming from private sources whose
incentive might be to disprove AGW.  In fact, just this year, President
Bush declared that the US Government alone spent more money on AGW research
than on AIDS research, and the US is actually late in the climate funding

Recently, Greenpeace criticized ExxonMobil for exercising
its free speech rights and giving
about $2 million to global warming skeptics

Still, the Greenpeace report is already receiving
scrutiny in Washington, where Rep. Brad Miller, a North Carolina Democrat, has
joined the environmentalist group in calling for Exxon to release its plans for
contributions during the current year.

"The support of climate skeptics, many of whom
have no real grounding in climate science, appears to be an effort to distort
public discussion about global warming," Miller said. "So long as
popular discussion could be about whether warming was occurring or not, so long
as doubt was widespread, consensus for action could be postponed."

Incredibly, at these spending rates, skeptics are getting outspent by AGW
supporters something like 1000:1 or more.  It is astounding that AGW
supporters, with such a huge funding and publication advantage, still feel
threatened by critics.

Climate research, once a sleepy academic backwater, is now a
multi-billion dollar industry.  This boom in spending is because of fears
of AGW, and should AGW theory be discredited, this funding will quickly dry
up.  So funding for climate researchers exists only as long as climate
researchers beat the drum that AGW is a large threat.   It strikes me
that this is at least as large an incentive for bias as that of any
Exxon-funded skeptic.   Here's another way to look at it:  If
AGW theory is proven correct, the likely political response might cut Shell's
revenues by 20-30%, at most.  If AGW theory is proven incorrect, then
university climate research funding might be cut by 100%.
  Directionally, all the incentives in academia are to inflate global
warming projections.  No one is going to make the news, or even continue
to get funding, if they argue that warming will only be a degree or two in the
next century.  The guys that get the fame and the grants are those pushing
the numbers higher and higher.

Certainly AGW supporters claim that academic researchers are
only concerned about the science and are not concerned about the funding
incentives.  This may be true (though a bit naÃ¯ve, for anyone who has been
in a university environment and sought research funding), but if pro-AGW
researchers are not swayed by the funding, then it should be equally true that
AGW skeptics are not swayed by much smaller amounts of money flowing to
them.    Any argument that tries to claim that these situations
are somehow different just ends up being circular, i.e. "it's OK if our guys do
it because our guys are right."

One of the mistakes the IPCC process has systematically made
is to make the lead author's and reviewers of many of its report sections a
scientist whose research is mostly in that area.  While this makes a
certain sense, as these people will be expert in their particular area of
review, it presents them with a huge conflict of interest.  For example,
Michael Mann used his own historical temperature reconstructions as the lead
analysis in the section of the third IPCC report for which he was lead
author.  Clearly, one wouldn't expect him to be (nor was he) open to any
research or issues or criticisms aimed at his own work.  In the fourth
report, the new lead author who replaced Mann on this section (Biffra) did the
exact same thing Mann did "“ used his own work as centerpiece of the section,
and has refused to even consider criticisms about that work. 

Just to avoid future argument, I
will outline my potential biases.  I own a small recreation business which
depends on people traveling to beautiful, natural settings.  I lose
business when the climate changes (e.g. when lakes dry up next to my
facilities, which has happened to me).  I generally gain business when gas
prices increase, as they might under various anti-global warming mandates,
since my facilities tend to be short-drive weekend destinations rather than cross-country
destinations.  I grew up in Houston, Texas, so most of my family has
worked in the oil industry at one time or another, and I worked for the Great
Satan Exxon as my first job for three years out of college.  I am a
libertarian blogger at, and am suspicious of government
interventions but have historically supported emissions limits where they make
sense.  No one has contributed any money to me for this paper or for the
operation of my blog.

The Climate Trojan

To fully understand the passionate, almost dogmatic
dedication so many people have to AGW theory, it is a bit useful to look at a
little history.  After the fall of the Soviet Union in 1989, there were a
lot of Marxists, socialists, anti-corporatists and anti-capitalists who were
looking for a new way to package and reinvent themselves, given that the vast
majority of people (at least in the West) considered socialism failed and no
longer wanted to hear about it any more.  For a while, many of these folks
latched onto the anti-globalization cause.  Every interview I ever saw of
one of these anti-globalization guys was a real mess of disorganized beliefs,
but one could tell the movement was the new home for anyone who wanted to stop
the spread of capitalism and privately-owned business. 

Then, along came anthropogenic global warming.  Here
was a theory and movement that united many disparate interests:

  • Socialists, communists, and Marxists
  • Anti-capitalists
  • Anti-consumerists
  • Those opposed to large corporations
  • Those opposed to global free trade
  • Those opposed to economic development and growth, longing
         for simplicity
  • "Buy local" movements
  • People who just hate oil companies

Suddenly, here was a big tent for all of these causes.
I highly encourage you to view a global warming rally.  Don't just watch
the snippets on the evening news, those usually highlight the most reasonable
speakers at the rally.  Actually go and watch the whole event.  What
you will see is far more anti-corporate, anti-oil company, anti-capitalist
rhetoric than you will hear climate science and discussion.  The two
rallies I have seen with my own eyes were Marxist rallies under a climate
banner.  As an admittedly extreme example, I will refer you to the words of
Watson, Founder and President of Sea Shepherd Conservation Society
, who
offers his group's vision.  While this particular vision pre-dated most
discussions of AGW, I hope you can see how AGW fear-mongering provides quite a
useful vehicle for groups of this type:

"We need to radically and
intelligently reduce human populations to fewer than one billion.... We need to
stop burning fossil fuels and utilize only wind, water, and solar power with
all generation of power coming from individual or small community units like
windmills, waterwheels, and solar panels. Sea transportation should be by
sail.... Air transportation should be by solar powered blimps when air
transportation is necessary. All consumption should be local. No food products
need to be transported over hundreds of miles to market. All commercial fishing
should be abolished. If local communities need to fish the fish should be
caught individually by hand. Preferably vegan and vegetarian diets can be
adopted.... We need to remove and destroy all fences and barriers that bar
wildlife from moving freely across the land.... We need to stop flying, stop
driving cars, and jetting around on marine recreational vehicles.... Who should
have children? Those who are responsible and completely dedicated to the
responsibility which is actually a very small percentage of humans...."

Of course what he doesn't say, but is an explicit outcome of
this vision, is that we can all go back to being dirt poor and having a life
expectancy of about 40 years.

The average person, say in America, wants little to do with
any of this.  But fear of AGW provides a way to engage everyone in the
movement.  Socialists of all stripes no longer have to spew Marxist
notions that turn most people off; now, they can talk the science of global
warming and hurricanes and massive floods and such, and, using fear, trample
the average guy into their socialist goals of stifling capitalism, growth, and
having the government take over the economy through this environmental

The Need to

One of the hardest parts of really trying to understand what is going on in
the AGW scientific debate is separating the scientists doing real science from
the political advocates, who sometimes carry quasi-scientific titles.  A
very, very small number of vocal climate scientists and a somewhat larger group
of what I would call advocates and bureaucrats really determine what you hear
in the media about AGW science.   A great example is the UN IPCC
reports.  Unless you have gone online and dug into the detailed reports
themselves, likely all you have seen from these reports is taken out of the
management summaries "for policy-makers".  These summaries are written by
bureaucrats and advocates, not so much by scientists, and tend to wildly
mis-characterize the true state of the science.   Careful language in
the heart of the reports expressing uncertainty and low understanding of
certain phenomena are cast aside in the summaries, in favor of a comforting
certainty and absolutes.  In earlier IPCC reports, this caused notable
disconnects between the summaries and the detailed science.  More
recently, the UN has "fixed" this problem by having their non-scientists write the
conclusions in the management summaries first, and then telling authors of the
individual sections of the report to conform their writing, and their science,
to the summary.  So, for the Fourth IPCC report, the summary was published
over a half year before the science!

As a result, while the IPCC reports claim to be the consensus of 5000
scientists, actually less than half would willingly sign their name to the
management summaries of their work that you see in the press.  The
management summaries and related press releases have become more political
advocacy than science, as UN bureaucrats use AGW-fear-mongering to increase
their prestige and power.  Generally, these summaries and press releases
are taken more seriously by the press than they are climate scientists.
You can get an insight on the IPCC process just by looking at how they select
their co-lead authors on certain sections.  A logical way to choose these
authors would be to find scientists who bring a different scientific perspective
"“ maybe a leading astronomer who studies the sun, maybe someone who studies
hurricanes, or perhaps even, gasp, a skeptic or two.  This is not how the
IPCC makes the selection.  Instead, they focus on including scientists,
often with limited experience or expertise, who bring geographic or ethnic
diversity to the panel.  Nothing better demonstrates that the IPCC is
first and foremost a political entity, and a scientific body second (at best).

If I seem too hard on the climate science community, then consider this quote
from National Center for Atmospheric Research (NOAA) climate researcher and
global warming action promoter, Steven Schneider:

We have to
mention of any doubts we have. Each of us has to decide what the right balance
is between being effective and being honest.

Is that how you learned science in high school "“ that lying
about the science was OK if it makes you more politically effective?  Der
, a magazine historically sympathetic to the AGW cause, published
this analysis:

This doesn't mean that Gore should necessarily be
taken to task for his statements. He is a politician. But it is odd to hear
IPCC Chairman Pachauri, when asked what he thinks about Gore's film,
responding: "I liked it. It does emotionalize the debate, but it seems
that it has to do that." And when Pachauri comments on the publication of
the first SPM by saying, "I hope that this will shock the governments so
much that they take action," this doesn't exactly allay doubts as to his
objectivity. When Renate Christ, the secretary of the IPCC, is asked about her
opinion of reporting on climate change, she refers to articles that mention
"climate catastrophe" and calls them "rather refreshing." .
. .

The problem is that the IPCC is not a political
group whose goal is to exert pressure, but a scientific institution and panel
of experts. Its members ought to present their results and analyses
dispassionately, the way pathologists or psychiatrists do when serving as
expert witnesses in court, no matter how horrible the victim's injuries and how
deviant the perpetrator's psyche are.

I will end this section on an admittedly extreme example
of a headline taken from the Canadian, a "progressive" magazine up in
the Great White North.  In the great race to one-up other media outlets in
creating a panic, and not happy with just a few more hurricanes or some melted
icebergs, the Canadian has taken the prize.  Get ready for it"¦

"Over 4.5 Billion people could die
from Global Warming-related causes by 2012"

In case you are struggling with the math, that means that they believe
Global Warming could kill three quarters of the world's population in the next
five years.  And the media treats these people with total respect, and we
skeptics are considered loony?


The open comment thread for this paper can be found here. 

Chapter 7: The Effects of Global Warming (Skeptics Guide to Global Warming)


There is no area in global warming discussions where AGW
advocates have done more to shoot down their own credibility than in the
absolutely egregious science and absurd claims that have been made about the
potential negative effects of global warming.  If AGW advocates are frustrated
that skeptics question their science and their credibility, they need to look
no further than their own claims on global warming effects, which are so easy
to prove wrong that it causes people like me to question everything else they

Why only bad stuff?

Whenever global warming is discussed in the press, the
consequences are all universally bad.  Floods, famine, drought,
pestilence, disease "“ they are all commonly predicted results of global
warming.  But it is worth noting that in the 1970's, when climate
scientists and the press were in a panic over global cooling, the predicted
results were"¦ floods, famine, drought, pestilence, disease.  The
implication is that we currently happen to be balanced on the knife edge of
exactly the optimum world temperature for mankind.  Any change warmer or
cooler results in net negative consequences.

This, of course, seems an odd coincidence.  Since man
evolved into homo sapiens, he has experienced a wide range of cooler and
warmer temperatures than we experience today.  It seems frankly amazing
that in the mid 20th century we happened to be sitting at the
absolute ideal temperature for modern technological society and
agriculture.  Now, I guess you can argue that our society has made
enormous investments based on the locations of the best crop lands, the height
of the oceans, the typical paths of storms, etc., and that shifts in any of
these would force an expensive restructuring of these investments.
However, it is also worth noting that from the bottom of the Little Ice Age to
say 1980, the world warmed at least a degree, and no one really
noticed!  Everyone was still talking about cooling!

So I think that any honest analysis of the effects of global
warming would have to acknowledge that there are likely both positive and
negative effects.  While some areas may experience heat-induced droughts,
other will be wetter as more moisture from the oceans is evaporated.
While some crops will struggle, others, particularly in northern latitudes, will
thrive due to longer growing seasons.  For each crop of vegetables that
wilt in a heat wave there will be a crop of citrus that didn't freeze.
While more may die from the heat, fewer will die from the cold.  These may
still net to a negative sum, but that net sum will be substantially less
negative than a one-sided look at only the downsides of warming would arrive

One reason that warming impact analysis is hard is because while we may talk
about the world warming a degree or two, the world does not warm evenly.
Most climate models show the most warming on dry winter nights  (Siberian
winters, for example, get a disproportionate share of the warming).  An
extra summer degree in Arizona would suck; an extra winter degree in Siberia
would probably be welcomed, and would likely extend growing seasons.

In the rest of this chapter, I will spend some time with a number of the
most common "scary results" from global warming.

Ice melting / ocean rising 

In An Inconvenient Truth, Al Gore claims that oceans will
rise twenty feet due to global warming.  Helpfully, a number of websites
have been created to show what parts of the world (including much of Florida)
would sink beneath the oceans like Atlantis with a 20-foot rise in sea level.

Fortunately, even most AGW supporters believe that Gore is
wildly exaggerating, at least for any time period less than a couple of
centuries.  The Fourth IPCC report (see chart below) predicts sea level
rise by the year 2100 of "¦ 12-15 inches.  And remember that this is based
on forecasts of both CO2 production and climate sensitivity to CO2 that are
arguably high by a factor of two or more.  From the fourth IPCC report
(different columns are for different starting CO2 forecasts):

By the way, to give a sense of scale, the IPCC estimates
that the oceans have already risen about 0.2 meters in the last 130 years or

One other interesting thing you can see from the sea level
forecast chart is that even the IPCC considers ice melting virtually
irrelevant.  That is because most of the surface level increase is from
thermal expansion of the water as the oceans warm.  In the A1B case, for
example, net worldwide ice melt raises oceans by about 4 inches in the next
hundred years. 

This last conclusion may seem crazy to anyone who has
watched the media of late or seen Mr. Gore's movie.  Images of ice
crashing into the ocean and sea ice retreating are common fodder for global
warming visuals.  But the fact is that ice, like everything else in
climate, is complicated.

  • North Pole:  Arctic sea ice melting is totally
         irrelevant to ocean surface levels.  Since the ice floats, even a
         100% melting of the Arctic ice will not change sea level one bit, just as
         ice melting in your glass of water does not cause your glass to

But some may argue that this ducks the
question.  Does current, well-documented retreat of artic ice sheets
provide independent confirmation of the magnitude of AGW?  In fact, though
ice sheets are retreating, this seems to be part of a two hundred year trend
that began long before man was burning fossil fuels in any quantity:

  • Alpine Glaciers:  We know that many Alpine
         glaciers around the world are retreating.  Some of this is surely
         from global warming, but some is also from fluctuations in
         precipitation.  In many cases, we have documented evidence that these
         glaciers have been retreating since the 19th century, and that
         they have been less extensive in the past.

Reid A. Bryson is Emeritus Professor and founding
chairman of the University of Wisconsin Department of Meteorology"”now the
Department of Oceanic and Atmospheric Sciences and a member of the United
Nations Global 500 Roll of Honor.  When asked about
the retreat of Alpine glaciers
, he says, "What do they find when the ice
sheets retreat, in the Alps?  A silver mine! The guys had stacked up their
only the snow never went," he says. "There used to be less ice than now. It's
just getting back to normal."

Alaska Geographic published a chart of the retreat
of the glaciers at Glacier Bay, Alaska, showing most of the retreat occurred before
the 2nd half of the 20th century:

One special note should be made of the glaciers on
Kilimanjaro, because their retreat over the last 125 years has been
well-documented and played a starring role in An Inconvenient Truth.  Analysis
has shown that most the glacial retreat at Kilimanjaro occurred before 1953
(and therefore before most recent warming) and that the retreat has
more to do with moisture in the air than with global warming
.  One
wonders why the movie, with glacial retreats around the world that are provably
due to warming, would focus on one that is probably not due to warming.

· Greenland: 
Greenland has a lot of ice, and there is not much doubt that if it all melted,
the oceans would rise a lot.  However, we know that in the middle ages,
Greenland was much warmer and had less extensive ice coverage (thus the name
Greenland and the successful attempt to farm it for over a century)

While there is a lot of discussion about whether
the Medieval Warm Period extended worldwide, most accept that it did cover the
North Atlantic, including Greenland.  Boreholes, such as the Dahl-Jensen
below, seem to prove out our historical information, showing a temperature peak
around the year 1000.

· Antarctica:
Something like 80-85% of the world's ice is in Antarctica.  And no one
really thinks it is melting or going to melt.  In fact, if you look at the
marks on the IPCC chart above for the contribution of Antarctic ice to ocean
levels, it has a net negative impact, which means the IPCC actually expects the
Antarctic ice sheet to grow, not melt.

Whoa, that can't be right!  Mr. Gore showed those videos of ice retreating
in Antarctica.  Well, yes, sort of.  Scientists expect that global
warming will make the sea currents that circle Antarctica a bit warmer, leading
to more precipitation and more snowfall on the continent.  Besides,
Antarctica is so damn cold that raising temperatures a few degrees is not going
to melt anything. 

The one exception is the Antarctic Peninsula, which
sticks out into the warmer oceans.  This land area, representing about 2%
of the Antarctic land mass and even less of its total ice sheet, is expected to
warm and lose ice while the other 98% gains ice.

Guess what?  Mr. Gore chose that little 2% to
illustrate his movie.  Was he ignorant of the choice he was making, or did
he know exactly what he was doing, telling the literal truth (that the
peninsula is melting) but leading viewers to the wrong conclusion overall about
Antarctic ice?

By the way, one last interesting
fact that frankly, scientists don't fully understand is the fact that the South
Pole is really not experiencing any warming.  While the warming at the
north pole exceeds the global average, the south pole shows little or no



Hurricanes & Tornados

Alter Hurricane Katrina, the media storyline focused
strongly on the role global warming may have played in increasing hurricane
power and activity.  Lost in the rush to blame global warming was the fact
that Katrina, when it made landfall, was not even a category 5 hurricane, and
its devastation was due more to  a city sited below sea-level that did a
poor job of managing its storm protection.

In fact, many hurricane experts do not agree with the argument
that warming oceans can lead to more and stronger hurricanes.  In fact,
hurricane activity is more related to the difference in temperatures between
the cold and warmer waters, a difference AGW theory says should decrease rather
than increase.  So is there reason to believe hurricanes are on the rise
as global temperatures warm?  The answer, as shown below, seems to be no:

But what about storm damage?  It certainly seems like
recent hurricanes have resulted in far more economic damage.  And they
have, but for the simple reason that over the last several decades, Americans
have put billions of dollars of expensive homes and other facilities in
vulnerable Gulf and Atlantic coast locations.   Several years ago, Dr. RA Pielke and CW Landsea
(that can't really be the name of a scientist studying coastal strikes by
hurricanes) attempted to correct hurricane damage numbers for the density and
value of coastal real estate:

By this reckoning, it is hard to see any trend.

Another claim Mr. Gore makes in An Inconvenient Truth
is that 2004 was the most active year for tornadoes ever in the United States,
and that there has been a steady trend in increasing tornados as the globe has

And certainly if you look at the raw numbers, you might be

But there is a little something Mr. Gore fails to
mention.  During this time period, from 1950 to 2000, the technology and
network for detecting tornados has improved vastly.  From the NOAA

With increased national doppler
radar coverage, increasing population, and greater attention to tornado
tornadoes that would have likely been reported even during the decades before
Dopplar radar use became widespread and practices resulted in increasing
the strongest tornadoes over the past 55 years.

Oops!  In fact, tornado frequency seems to be falling
as temperatures warm.  Do you think this was another honest mistake, like
with Antarctica, or did Mr. Gore purposefully obfuscate the real story?

Temperature Extremes

Another argument is that global warming will lead to more temperature
extremes, particularly record sweltering highs.  That seems logical
enough, but Bruce Hall actually
compiled the data and found something interesting.  He created a data base
for each state which shows in what year that state's monthly temperature
records were set.   So for each state, he has the years when the
twelve monthly high temperature records were set (e.g. year of highest Arizona
Jan temp, year of highest Arizona Feb temp, etc.) and the years when the twelve
monthly low temperature records were set.  Here, for example, is his data
for Arizona:


So, for example, the record for the highest July temperature was set in 1905
at Parker, Arizona with a scorching 127 degrees.  The entry in his
database would then be Arizona-July:  1905.  He notes that there is a
bias in the data toward more recent years, since if the record was set in 1905
and tied in 1983, only the newer 1983 date will show in the data.  I would
also observe that this data is uncorrected for urban heat island effects (as
cities urbanize they get hotter, and effect that is different than CO2-cause global
warming and is usually corrected for in global warming studies).  There is
also a bias towards the present in having more measurement points today than
100 years ago:  More measurement points means that, over a state, one is
more likely to pick up the true high (or low).

Though I have
other problems with the anthropogenic global warming hypothesis
, I have
never really doubted that the world has warmed up over the last century.
So even I, a skeptic, would expect a disproportionate number of the all-time
high temperatures to be in the last decade, particularly without UHI correction
and with the bias discussed above.  The global warming folks would argue
that the effect should be doubly pronounced, since they claim that we are
seeing not just a general heating, but an increase in volatility (ie more
extreme variation around the mean).

But Hall doesn't find this when he graphs the data.
Take the 600 state monthly high temperature records that exist on the books
today (50 states times 12 months) and graph the distribution of years in which
these records were set:

Assuming about 120 years of data, you should expect to see a high
temperature record on average in a database of 600 records at 5 per year, which
is precisely where we have been of late and well below the record years in the
thirties (remember the dust bowl?) and the fifties. It seems to actually show a
reduction in temperatures or volatility or both.

This may seem impossible "“ how can the mean increase without causing a lot
more new highs?  But remember what we discussed earlier "“ global warming
is expected to be seen disproportionately in nighttime and winter
temperatures.  This means that the mean can increase even as daytime
summer highs don't increase much.  In a sense, is the lows, not the highs,
that are getting higher.

Vincent et al in 2005 did a study of temperature trends in South America
from 1960-2000.  What they observed is exactly what we discussed
here:  The number of warm days and cold days did not really change.
The warming trend showed up as a decrease in cold nights and an increase in
warm nights, meaning effectively that the diurnal (across 24 hours) temperature
variation is narrowed. 

It's a little hard to be scared by this.

Extinction and Disease

Biologist Josef Reichholf was
interviewed recently in der
.  He is a strong conservationist, and certainly has his axe to
grind with industrial society.  In fact he blames industrial agriculture
and modern development for problems that species face. 

Many species are certainly
threatened, but not by climate change"¦.Many species have already fled from the
countryside to the cities, which have been transformed into havens of
biodiversity. We are also seeing another interesting phenomenon: Major cities,
like Hamburg, Berlin and Munich, have formed heat islands where the climate has
been two or three degrees warmer than in the surrounding countryside for
decades. If higher temperatures are truly so bad, why do more and more animals
and plants feel so comfortable in our cities?

On the contrary, there is much to
be said for the argument that warming temperatures promote biodiversity. There
is a clear relationship between biodiversity and temperature. The number of
species increases exponentially from the regions near the poles across the
region is, the more diverse are its species.

OK, but what about those polar bears?  We have all seen
the media pictures of bears stranded on blocks of ice, as if all the arctic has
melted out from under them.  Well, it turns out that polar bears have
survived much warmer conditions.  We know polar bears existed as a
separate species at least 125,000 years ago, and in the intervening years,
there have been periods where Arctic sea ice melted completely during the
summer months.  And yet polar bears still exist today.  Polar bears
may be threatened by man's hunting and encroachment on its hunting grounds, but
not likely by our fossil fuel combustion.

AGW fear-mongering also extends to breathless predictions of
increases in "tropical" diseases.  Reichholf also takes on this canard:

Many people truly believe that
malaria will spread as temperatures rise. But malaria isn't even a true
tropical disease. In the 19th century, thousands of people in Europe, including
Germany, the Netherlands and even Scandinavia, died of malaria, even though
they had never gone abroad. That's because this disease was still prevalent in
northern and central Europe in previous centuries. We only managed to eliminate
malaria in Europe by quarantining the sick, improving hygiene and draining
swamps. That's why I consider it virtually impossible that malaria would return
to us purely because of climate change. If it does appear, it'll be because it
has been brought in somewhere.

Most of the world's leading tropical disease experts tend to
agree with Reichholf.  In fact, I would argue that diseases like Malaria
are not diseases of the tropics but diseases of poverty and
under-development.  Malaria is prevalent in Africa not because Africa is
hot but because Africa is poor.  Asian tropical countries that have developed
substantially over the last several decades have also greatly reduced
malaria.  In fact, as I will discuss in later sections, by reducing world
economic growth and slowing development in the third world in the name of CO2
reduction, we will actually increase rather than reduce these diseases.

Collapse of the Gulf Stream and Freezing of Europe

One of the recent hysteria's has been that global warming
will cause the Gulf Stream to collapse as Atlantic circulation patterns are
radically altered, thus leading to the freezing of Europe.  More sober
scientists have since essentially said "nevermind."  The Gulf Stream and
Atlantic circulation patterns are far more robust than this theory assumed,
and, even if the Gulf Stream changes, proponents of the theory were
overestimating the dependence of Europe on Gulf Stream warming.

Non-warming Effects of CO2

Interestingly, we may eventually decide that other
non-climate effects of CO2 production actually present more tangible
environmental threats.  In particular, recent studies have shown that more
atmospheric CO2 is causing the PH of ocean surface layers to drop (ie become
more acidic) leading potentially to coral kills and substantial changes in sea
life.  At the same time, physicist Freeman Dyson argues that stratospheric
cooling from man-made CO2 is much more a problem than surface warming, and is
much more measurable and provable.  These topics are beyond my scope at
this point, but something we may see more of in the future.


The open comment thread for this paper can be found here. 

Global Warming Movie

I finally watched the BBC special Global Warming Swindle and have to say that it presents a pretty good counter-hypothesis to the prevailing theory of anthropomorphic CO2 production to explain recent global temperature changes.  It also hits some good points on what might be motivating the hard core of the environmental movement beyond just concern about global warming, and why the costs of CO2 control are so high.

I have historically accepted the basic hypothesis of anthropomorphic global warming but have been skeptical of the exaggerated outcomes (Al Gore's 26 foot sea-level rise, for example, which is 17 times more than even the IPCC predicts over the next century) and have posited that a warmer but richer world may well be better than a cooler but poorer one.  I have also pointed out the uncertainties in the IPCC analysis that never get mentioned in the press, like the huge uncertainty in the feedback loops that drive much of the temperature change in current models.  For example, the IPCC admits they don't even know the sign of the largest feedback loop (clouds), which is a big uncertainty since about 2/3 or more of the warming in the models come not directly from CO2 but from these feedback loops.

Anyway, most of my past skepticism has been within the framework of these IPCC studies.  However, this documentary casts off the whole framework, offering a counter-hypothesis of solar activity to explain temperature variations.  I thought the most interesting part of the documentary was when they showed Al Gore from An Inconvenient Truth with a multi-thousand year plot of temperature and CO2.  The chart certainly looks compelling, but this movie makes the point that while the two lines move together, the CO2 line is lagging the temperature line by five hundred years.  Meaning that CO2 levels may be linked to temperature, but the causality may be opposite of that implied by Gore. 

The documentary goes on to offer solar activity as an alternative explanation, with graphs of moving curves of solar activity and temperature that seem to show at least as much correlation as Gore's CO2 graphs.  They hypothesize that rising temperatures driven by changes in solar
activity heat up oceans over time and cause them to release CO2 into
the atmosphere.  I don't think the evidence is definitive, but it certainly casts doubt as to whether we really know what is going on.  I always thought it a bit odd that people would search for the causes of changing temperatures without first checking out the sun, sortof like walking in a room that is too hot and trying to fix it without first checking the thermostat.  This is particularly true given new evidence that other planets are warming, presumably due to solar activity (unless, of course, it's an Exxon plot).

By the way:  Advocates of the anthropomorphic theory are criticizing this movie in part because it does not use Mann's hockey stick temperature chart.  Sorry, but if they want to claim the scientific high ground, I think they need to stop tying their argument to this weak study.  Statisticians have dumped on it repeatedly (apparently random white noise fed into their model produces a hockey stick) and the evidence for eliminating the Medieval warm period is based on the rings in one or two trees.

I Wish I Could Like Activists

I sure wish I could like activists like Al Gore.  Last night, at the Oscars, he was charming and passionate.  He has something he cares deeply about and flies around the world speaking about.    It's terribly compelling, which you could see in the reaction Al got last night from an adoring audience and various fawning actors.

And if Mr. Gore were there last night to convince the audience to get out of their stretch limos and G-V's and drive Prius's and use compact fluorescent bulbs, I'd be fine.  Sure I might laugh that it was all pointless and the movie Inconvenient Truth was terribly overblown, but its a free society and Mr. Gore would be welcome to make his call to other individuals that they change their lifestyle. 

Unfortunately, Mr. Gore's only goal last night was not just to rally the TV audience to change its lifestyle.  The more important goal was to increase the likelihood that government will compel Americans to do what Mr. Gore wants.  And this is what makes me cringe nowadays when I hear the term "activist."  I don't want to cringe, because passionately advocating for you cause, even if I disagree with it, should be part of the rich fabric of a free society.  Unfortunately, though, at the heart of nearly every modern activist's agenda is compulsion -- the desire to use the coercive power of the government to force you to do something you would not otherwise choose to do.  It is the very unusual activist today who is not trying, whether they admit it or not, to chisel away at individual freedom for some "higher cause."

By the way, speaking of higher cause, did anyone else note the religious parallels in the green-speak last night at the Oscars?  You had Al Gore in the role of Bill Graham, with several people talking about how Al had helped them "see the light."  Even more amazing to me was the parallel with a confessional at Catholic Church.  I have been lucky enough in the past to attend the Academy Awards, and I can tell you from experience what was sitting right outside:  The largest collection of stretch limousines you can ever imagine -- I am talking about enough limos to create a traffic tie-up four lanes wide and extending back for miles, all running their engines for six hours waiting to whisk stars to late-night parties and private jets.  I am fairly certain that no other small group in America generated more CO2 yesterday through their private use than the audience at the Oscars.  Yet by declaring the Oscars to be "green", voting for an Inconvenient Truth, and cheering Al Gore, the audience was in effect saying 10 hail mary's in the confessional, washing away all sin. 

Update:  How I can be sure Al Gore's activism is about government control and not individual action:

Drudge reports  that Al Gore's Nashville mansion consumes more than 20 times the average amount of power for an American household.

Gore's whole deal is that civilization-saving absolutely and vitally
(Unless Gore's house is powered completely or partially off a
Drudge's piece.)

Does Gore's seeming inability to curb his
power consumption--which has apparently grown since the release of his
Oscar-winning flick--mean it isn't true that we really do all
have to scrupulously use less carbon-burning energy or doom the planet?
No. But it does make it a little hard to believe that he really
believes it--or that if even the biggest believer in global warming of
all can't control himself in this regard, that a serious planetwide
reduction in the short or medium term short of draconian outside
controls has much hope.

I Find This Argument Uncompelling

I am skeptical of some but not all global warming claims, but must admit that even as a skeptic, I find this argument by James Lewis uncompelling:

Now imagine that all
the variables about global climate are known with less than 100 percent
certainty. Let's be wildly and unrealistically optimistic and say that
climate scientists know each variable to 99 percent certainty! (No such
thing, of course). And let's optimistically suppose there are only one-hundred x's, y's, and z's
--- all the variables that can change the climate: like the amount of
cloud cover over Antarctica, the changing ocean currents in the South
Pacific, Mount Helena venting, sun spots, Chinese factories burning
more coal every year, evaporation of ocean water (the biggest
"greenhouse" gas), the wobbles of earth orbit around the sun, and yes,
the multifarious fartings of billions of living creatures on the face of the earth, minus,
of course, all the trillions of plants and algae that gobble up all the
CO2, nitrogen-containing molecules, and sulfur-smelling exhalations
spewed out by all of us animals. Got that? It all goes into our best
math model.

in the best case, the smartest climatologist in the world will know 100
variables, each one to an accuracy of 99 percent. Want to know what the
probability of our spiffiest math model would be, if that perfect world existed?  Have you ever multiplied (99/100) by itself 100 times? According to the
Google calculator, it equals a little more than 36.6 percent.

The Bottom line: our best imaginable model has a total probability of one out of three. How many billions of dollars in Kyoto money are we going to spend on that chance?

Yes, there is a point to be made that climate is really complicated.  However, I can still make correct and valid directional predictions without knowing the exact state of every variable.  For example, I can say with some certainty that, at least here in Arizona, that the temperature at 4PM is going to be higher than the temperature at 4AM, and probably by many degrees.  I can make this statement despite having no idea what the temperature at either time actually is.

I think one can say that the hypothesis is pretty strong that man-made CO2 is increasing atmospheric CO2 concentrations which in turn is causing some warming.  Where Mr. Lewis probably has a point is on the issue of positive and negative feedbacks.  Most of the warming in the estimates in productions like "An Inconvenient Truth"  relies not on just CO2-driven warming, but warming from a variety of feedback processes.  These feedbacks are really really complicated and not well understood.  I discuss this issue of feedbacks both here and here and here.

(HT Maggies Farm)

The Obesity Non-Epidemic

It seems of late that obesity is the new sky-is-falling health care issue I see in papers all the time.  One of the easiest ways to create a "trend" is to steadily change the standards**, which is in fact what has been happening with obesity in the US.  Every year or two, government officials or whoever does this stuff expand the range of weights that constitute "obese".  By doing this, even if the average weights are not changing (and I don't know if they are or are not) you can create a trend in increasing obesity just from changing the standards.  In fact, I argued here:

By the way, I am willing to make a bet with anyone that no where near
40% of our healthcare charges in Arizona are due to obesity.  I am
positive some advocate made up this number, or created it using some
ridiculously broad assumptions, and it has now been swallowed by the
credulous and scientifically-illiterate press. 

Sandy Szwarc who runs the new Junkfood Science blog, writes of a similar effect in hospital statistics.

The HCUP report
is not actually reporting hospital stays of obese people. It is a tally
of the numbers of times "obesity" was checked off on the billing codes
on the hospital records. These codes are currently known as ICD-9
codes, taken from the International Classification of Diseases, Ninth Revision.
This is an enormous, complicated and continually changing system which
gives a number to every disease and medical procedure, and currently
has about 12,000 codes. The medical literature is filled with
documentations of their inaccuracies in reflecting actual patient
disease rates. But over recent years, healthcare providers are being
increasingly educated on using these codes in order to receive
reimbursements ... including coding for obesity. The weight loss and
bariatric industry has been especially intense in marketing the usage of the obesity code, in particular.     

Not surprisingly, more providers are.    

So that 112% increase in hospitalizations for "obesity"since 1996 actually reflects increased usage of
the coding, but whether or not it means there are actually more obese
patients is arguable. But with the heightened stringency and
surveillance by third party payers in compelling providers to
accurately note ICD-9 codes in order to receive reimbursements, the
current figures are certainly more complete than in past years.

She concludes by questioning whether there really is an epidemic of hospital admissions for obesity.  Remember that this is important because it is this obesity epidemic that is used as justification for nanny-state interventions like the NY trans-fat bans as well as potential tobacco-clone litigations against fast food companies. 

This report is being
presented as proof that ""˜obesity' has become a major public health
problem." That was even its opening sentence. But the media's failure
to give us the full story is demonstrated in the most significant fact
in the report: 94.3% of all hospitalizations made no mention of obesity!    

Fat people are not flooding into hospitals with health problems more than anyone else.   

"Obesity" is the primary diagnosis in only 0.4% of all hospitalizations and
virtually all of those (95%) were for bariatric surgery! Not the result
of fat people succumbing to life-threatening health problems, but a
profit-making elective surgery targeting them.

My sense is that the obesity issue is the next phase of what I call the health care trojan horse (and here and here).  This is the practice of using government funded health care expenditures as an excuse to micro-regulate our eating and other personal practices.  As I said then:

When health care is paid for by public funds, politicians only need to
argue that some behavior affects health, and therefore increases the
state's health care costs, to justify regulating the crap out of that
behavior.  Already, states have essentially nationalized the cigarette
industry based on this argument.

** As an aside, a fantastic example of this game is in the movie "An Inconvenient Truth."  The filmmakers try to make the argument that global warming is making weather more volatile.  As "proof", they show the number of reported tornadoes in the US rising dramatically since the 1950's.  But here is the rub:  In the 1950's, we had no good way of detecting smaller class 1 and 2 tornadoes that we now detect using Doppler radar and the like.  This means that we do not necessarily experience more tornadoes, we just can detect more.  In fact, if you look only at larger class 3-5 tornadoes that we could detect through the whole period, the tornado frequency has NOT gone up.  I leave it to the reader to decide if the filmmakers are terrible at interpreting scientific data, or if they are disingenuous.  Neither reflects well on the rest of the film.

Squashing Dissent

The word "censorship" is used all-too-often in this country.  I take a much more narrow definition of censorship.  In my mind, only the government can be guilty of true censorship, which I define as using the coercive power of government to prevent certain forms of speech.  By even this narrow definition, the recent threats against Exxon by Senators Jay Rockefeller and Olympia Snowe come awfully close to censorship:

We reprint the full text of the letter here,
so readers can see for themselves. But its essential point is that the
two Senators believe global warming is a fact, and therefore all debate
about the issue must stop and ExxonMobil should "end its dangerous
support of the [global warming] 'deniers.' " Not only that, the company
"should repudiate its climate change denial campaign and make public
its funding history." And in extra penance for being "one of the
world's largest carbon emitters," Exxon should spend that money on
"global remediation efforts."

Senators aren't dumb enough to risk an ethics inquiry by threatening
specific consequences if Mr. Tillerson declines this offer he can't
refuse. But in case the CEO doesn't understand his company's jeopardy,
they add that "ExxonMobil and its partners in denial have manufactured
controversy, sown doubt, and impeded progress with strategies all-too
reminiscent of those used by the tobacco industry for so many years." (Our emphasis.) The Senators also graciously copied the Exxon board on their missive.

is amazing stuff. On the one hand, the Senators say that everyone
agrees on the facts and consequences of climate change. But at the same
time they are so afraid of debate that they want Exxon to stop
financing a doughty band of dissenters who can barely get their name in
the paper. We respect the folks at the Competitive Enterprise
Institute, but we didn't know until reading the Rockefeller-Snowe
letter that they ran U.S. climate policy and led the mainstream media
around by the nose, too.

While I tend to believe that the warming camp is correct that manmade CO2 is creating or will create some global warming, there are a lot of very very good reasons to be skeptical of the magnitude of their warming estimates and their hysterical calls for massive government intervention in the world economy.  I call this the skeptical middle ground on climate.  (Update: more reasons to be skeptical of current "consensus" models here).  A skeptics guide to An Inconvenient Truth is here.

The "Nature" of Modern Scientific Consensus

I am often told, in emails that vary from friendly to downright threatening, that global warming science is not scientific consensus and my skepticism puts me on par with tobacco company lobbyists.  An upcoming paper in Theoretical and Applied Climatology looks back at a recent peer-reviewed Nature article that purported to provide more evidence for man-made global warming and found the much quoted article by Isabel Chiune in Nature to be complete crap:

What is important here is not the truth or falsity of
the assertion of Chuine et al. about Burgundy temperatures. Rather,
what is important is that a paper on what is arguably the world's most
important scientific topic (global warming) was published in the
world's most prestigious scientific journal with essentially no
checking of the work prior to publication.

Moreover "” and crucially "” this lack of checking is not the result
of some fluke failures in the publication process. Rather, it is common
for researchers to submit papers without supporting data, and it is
frequent that peer reviewers do not have the requisite mathematical or
statistical skills needed to check the work (medical sciences
excepted). In other words, the publication of the work of Chuine et al.
was due to systemic problems in the scientific publication process.

The systemic nature of the problems indicates that there might be
many other scientific papers that, like the paper of Chuine et al.,
were inappropriately published. Indeed, that is true and I could list
numerous examples. The only thing really unusual about the paper of
Chuine et al. is that the main problem with it is understandable for
people without specialist scientific training. Actually, that is why I
decided to publish about it. In many cases of incorrect research the
authors will try to hide behind an obfuscating smokescreen of
complexity and sophistry. That is not very feasible for Chuine et al.
(though the authors did try).

Finally, it is worth noting that Chuine et al. had the data; so they
must have known that their conclusions were unfounded. In other words,
there is prima facie evidence of scientific fraud. What will happen to
the researchers as a result of this? Probably nothing. That is another
systemic problem with the scientific publication process.

Oops.  By the way, accepting the hypothesis that man made CO2 is causing some warming does not require that one also accept Al-Gore-type estimates of catastrophic 6-8 degrees C warming or more in the next 50 years.  In fact, the evidence still is that man-made warming effects will be small, and predictions of massive warming are way out on a scientific limb with little proof.  I discuss these issues in my article on the skeptical middle ground on climate, as well as my earlier primer on an Inconvenient Truth.

A Skeptics Primer for "An Inconvenient Truth"

Update:  Please enjoy this post; however, I have published a (free) more comprehensive guide to the skeptics arguments concerning man-made global warming.  You can find the HTML version here and a free pdf download here.

A few days ago, my wife announced to me that she wanted me to take her to
"An Inconvenient Truth", the recent movie vehicle for communicating
Al Gore's views on climate change.  I told my wife that I found the
climate issue incredibly interesting -- I have always had a passion for
inter-disciplinary science and climate requires integration of bits not just
from climate science but from economics, statistics, biology, and more.  I
told her I would love to see a true documentary on climate change, but I was as
interested in seeing a "science" film from the group that put this movie
together as I presume she was in seeing a "even-handed" movie on
abortion produced by the Catholic Church.

Never-the-less, she has insisted, so I put together a skeptic's primer for
her, which I will also share with you.  Note that I am not actively involved in climate research myself, so the following is my admittedly incomplete understanding of all the issues.  It is meant to raise issues that you may not find discussed in most global warming accounts.

Overview:  The earth has warmed by 2/3 of a degree to as much as a degree (all temperatures in Celsius)
over the last 100 years, of which man may be responsible for no more than half
through CO2 emissions.  The poles, which are important to all the global
deluge scare scenarios, have warmed less than the average.  Man's CO2
emissions will warm the earth another degree or so over the next 100
years.  There is a possibility the warming will be greater than this, but
scary-large warming numbers that are typical of most climate reports today
depend on positive feedback loops in the climate that are theoretical and whose
effect has not yet been observed.  The effects of warming will be a mix of
positive and negative outcomes, recognizing that the former never seem to get
discussed in various media scare stories.  If the effects of warming are a
net negative on mankind, it is not clear that this negative outweighs the costs
in terms of lost economic growth (and the poverty, disease, and misery that
comes with lower growth) of avoiding the warming.  In other words, I
suspect a warmer but richer world may be better than a cooler but poorer world.

The Hockey Stick:  The Hockey Stick graph as become the emblem,
the sort of coat-of-arms, for the climate change intelligentsia.  Until
recently, the climate consensus for the last 1000 years, taken from reams of
historical records (things like the history of X river freezing in winter or Y
region having droughts) was this:


This chart is from the 1990 IPCC climate report, and in it you can see
features that both historians and scientists have discussed for years -- the
warm period during the Middle Ages and the "little ice age" of the
late 17th century.  Of course, this chart is barely better than a guess,
as are most all historical climate surveys.  For example, 3/4 of the earth
is water (where few consistent observations were taken) and only a small percentage of the rest was "civilized" to
the extent of having any historical records.  In addition to historical
records, scientists try to use things like ice cores and tree rings to get a
sense of long-term global climate patterns.

This long-held consensus changed with Mann, et. al., a study that created a new climate
picture for the last millennia that has immediately caught the fancy of nearly
every advocate of climate Armageddon.


For obvious reasons, this graph is called "the hockey stick" and
it is beloved by the global warming crowd because it hammers home the following
message:  Climate has been incredibly steady over the past 900 years with a flat to declining temperature trend until
man came along and caused a dramatic shift.  Based on this analysis, Mann
famously declared that the 1990's were the warmest decade in a millennia and
that 1998 was the hottest year in the last 1000 years.  (For real hubris, check
out this recent USAToday
, which purports to know the world's temperature within .001 degree
for every year going back two thousand years)

In fact, what Mann's chart shows for the last 100 years is about what I said in my overview - that
the world has warmed a degree and that man maybe has contributed up to half of
this.  Notice that tacked onto the end of the previous consensus view, the
last 100 years seem like it might just be the start of another natural cyclical
climate variation.    Not necesarily a reason for panic.  Ah,
but Mann's chart!  That's a chart that anyone eager to have the government
intervene massively in the economy is bound to love. It says that we are currently entering an unprecedented anomoly, and that the chief suspect for creating this change must be human civilization.

So is Mann right?  Well, a couple of things to note.  First, its
instructive to observe how eagerly the climate community threw out its old
consensus based on years of research in favor of Mann's study.  It's
unusual for a healthy
scientific community
to throw out their old consensus on the basis of one
study, especially when no one had replicated its findings independently.
Which no one has ever been able to do, since Mann has refused to share his
models or methodology details.  In fact, it took a US Congressional subpoena
to get any of his underlying models into the public domain.  This behavior
by a scientist would normally engender ENORMOUS skepticism in the community --
normally, I mean, except for in climate science, where mountaintop revelation without 3rd party repeatability
is OK as long as it supports a dire man-made climate catastrophe model.
In short, climate change advocates wanted the study to be true, because it was such a
powerful image to show the public.

Despite Mann's reticence to allow anyone to check his work, skeptics still
began to emerge.    Take that big temperature bulge in the Middle
Ages shown in the previous concensus view.  This bulge was annoying to climate
interventionists, because it showed that large variations in temperature on a
global scale can be natural and not necessarily the fault of modern man.
But Mann made this whole medieval bulge go away.  How?  Well, one of
the early revelations about Mann's work is that all the data before 1450 or so
comes from studying the tree rings of one single tree.  Yes, that's one tree
(1).  Using the evidence of this one tree, Mann flattened the temperature
over the 500 year period from 1000-1500 and made the Medieval warm period just go poof.  Wow!

The bigger criticism of Mann has come from statisticians.  Two Canadian
statisticians began questioning Mann's methodology, arguing that his
statistical approach was incorrect.  They demonstrated that Mann's
statistical approach was biased towards creating hockey sticks, and they showed
how the Mann model could be applied to random noise and produce a hockey
stick.   The climate change establishment did not take this criticism
well, and tried their hardest to rip these two guys up.  In fact, you might have believed that the two had been molesting little boys or declaring the world is flat rather than just questioning another scientist's statistical methodology. 

Recently, a US Congressional Committee asked a group of independent statisticians led by
Dr. Edward Wegman, Chair of the National Science Foundation's Statistical
Sciences Committee, to evaluate the Mann methodology.  Wegman
et. al. savaged the Mann methodology
as well as the peer review process
within the climate community:

interacting with the statistical community. Additionally, we judge that the
sharing of research materials, data and results was haphazardly and grudgingly
politicized that this community can hardly reassess their public positions
supported by his analysis.

Further, Wegman concurred on almost every point with the Canadians, coming to the conclusion that the hockey stick was deepfly flawed.  In most other scientific communities, the Mann analysis would have been sent
to the dustbin along with cold fusion and Archbishop James Ussher's dating of
the earth to October 23, 4004 BC.
The problem is that the Mann chart has become too politically important.  Prominent men
like Al Gore have waved it around for years and put it in his books.  No
one in the core of the climate community can back away from the hockey stick
now without the rest of the world asking, rightly, what else is wrong with your
analyses?  If I seem too hard on the climate science community, then
consider this
Steven Schneider:

the right balance is between being effective and being honest.

Now you know why, for all its flaws, you will continue to see the hockey
stick in the press.  Because it is not about the facts, but about "scary scenarios" and "dramatic statements".

Has Man Been Causing the Warming?

Yes, some of it.  But its a little more complicated than the global
warming community lets on.   First, note the last 100 years of the
hockey stick.  The big upwards spike begins in 1900, long before any large
man-made concentrations of CO2 were put into the atmosphere.  In fact,
even those most fanatical about assigning maximum blame for climate change to
man don't blame man-made effects for most of the first half of the 20th century
temperature spike. 

Which begs the question, what caused the 1900-1940 spike of about 1/2 a
degree?  Answer:  Nobody really knows.  Which begs the follow-on
question:  If we don't know what caused the 1900-1940 run-up, how do we
know that this same force is not responsible for some of the run-up since
1950?  Answer:  We don't.  As I will explain below, climate
scientists trying to validate their models have reasons for wanting the
post-1950 temperature rise to be all man-made.  But just because they
assume it to be due to man-made rises in atmospheric CO2 concentrations does
not make it so -- correlation does not equal causation.

Well, what else could be causing this increase?  It could at least partially be
cyclical variations in climate that we don't really understand.
Or it could be something more obvious, like, say, the sun was brighter.  I
can imagine your reaction -- no way it could be just a brighter sun,
Coyote.  I mean, that's the first thing the climate scientists would check
if earth temperatures were rising, right?


This chart compiled from data by Judith Lean of the Naval Research Library
and charted from her data at NOAA by
shows that interestingly, the sun's output does appear to be higher today than they have been in many, perhaps hundreds of years.  Would such increased activity be
expected to result in higher earth temperatures?  I don't know, but if you
think it odd that scientists talk about global warming without mentioning how
hot the sun is, well, welcome to the world of climate science.   Its kind of like scrambling to find out why your room is too hot without first checking to see where the thermostat on the furnace is set.  More
on the sun's variance
and climate change here

Future Warming:  The key question, of course, is about future warming - i.e.,
based on man's economic growth and projected output of CO2, how much can the
world be expected to warm, say over the next 50-100 years.  I don't know
what the movie "An Inconvenient Truth" will claim until I see it, but
most recent studies have shown warming from 2-8 degrees (consistent with what is depicted by the
USAToday graphic linked above).

There are lots of issues with these forecasts that occasionally might even get
mentioned in the popular press.  Some issues are unavoidable, like the
inherent complexity and unpredictability of climate.  Some issues probably
could be avoided, like the egregiously bad economic forecasting that drives CO2
output forecasts in many of these models.  I won't delve into these issues
much, except to say that we are dealing with massively complex systems.
If an economist came up with a computer model that he claimed could predict the
market value of every house in the world in the year 2106 within $10,000, would
you believe him?  No, you would say he was nuts -- there is way to
much uncertainty.  Climate, of course, is not the same as housing
prices.  It is in fact, much, much more complex and more difficult to

All these forecasts are created by a pretty insular and incestuous climate
dire forecast.  Certainly there are financial incentives to be as aggressive
channeled to the most pessimistic.   The global warming community spends
a lot of time with ad hominem attacks on skeptics, usually accusing them of
being in the pay of oil and power companies, but they all know that their own
funding in turn would dry up rapidly if they were to show any bit of skepticism
in their own work.

Leaving aside all the other modeling problems and focus on one fact:
Most climate scientists would agree that if you focus narrowly just on the
effects of CO2 on warming, that even under the most extravagant assumptions of
CO2 production, the world will not warm more than a degree or two in total,
some of which we have already seen.  The reason is that the effect of CO2
concentration on global temperature is logarithmic.  This means that
increasing concentrations of CO2 have diminishing returns on temperature.
For example, if the first doubling of CO2 concentration raises temperatures by
a degree, then the next doubling may only raise it by a tenths of a
degree.  This is because CO2 only absorbs sunlight and energy in certain
frequency bands and this ability to absorb energy gets saturated, much like a
pot of water can only dissolve so much salt before it is saturated.

There is fair amount of argument over just how saturated the CO2 layers are
in terms of energy absorption, but most scientists will agree that at some
point, in isolation, additional CO2 added to the atmosphere by man stops having
any significant effect on global temperature.

So how do we get these dire forecasts of 6, 7, 8 degrees of warming?
Well, I was careful to say the effect of CO2 in isolation maxes
out.  To get to higher levels of warming, scientists posit "positive
feedback loops" that augment the warming effect.  Positive feedback generally means that once a process gets going in a direction, there is some force that will accelerate the process
faster or farther in the same direction.  Negative feedback means that
once a process is moving there is some force that tends to try to slow the process back down.
Positive feedback is a boulder balanced on the top of a mountain, where one
push will cause it to roll down the mountain faster and faster; Negative
feedback is a boulder in a valley, where despite lots of effort, the rock will
keep coming to rest back where it started.

In global warming models, water vapor plays a key role as both a positive and a negative feedback loop to climate change.  Water vapor
is a far more powerful greenhouse gas than CO2.  It comes into play because CO2 driven warming will
put more water vapor in the atmosphere, because greater heat will vaporize more
water.  If this extra vapor shows up as more humid clear air, then this in
turn will cause more warming as the extra water vapor absorbs more energy and
accelerates warming.  However, if this extra water vapor shows up as
clouds, the cloud cover will tend to reflect energy back into space and retard
temperature growth. 

Which will happen?  Well, nobody knows.  And this is just one
example of the many, many feedback loops that scientists are able to posit but
not prove. And climate scientists are coming up
with numerous other positive feedback looks.  As one skeptic put it:

Regardless, climate models are made
interesting by the inclusion of "positive feedbacks" (multiplier
effects) so that a small temperature increment expected from increasing
atmospheric carbon dioxide invokes large increases in water vapor, which seem
to produce exponential rather than logarithmic temperature response in the
models. It appears to have become something of a game to see who can add in the
most creative feedback mechanisms to produce the scariest warming scenarios
from their models but there remains no evidence the planet includes any such
effects or behaves in a similar manner.

So, is it reasonable to assume these feedback loops?  First, none have
really been proven empirically, which does not of course necessarily make them
wrong.  More damning is the fact that models using mostly positive feedback
loops do a terrible job of modeling the last 100 years.  It is a perfectly
reasonable back check on any model to see if it predicts history.   Most of the aggressive climate models (ie the ones that tend to get quoted in the press) turn out to predict a warming for the
last 50 years far above what we have actually observed, which of course might make one
suspicious of their ability to predict the future.  A while back, I said
that climate scientists had a strong incentive to "claim" as much of
the 20th century warming as possible and attribute it to man.  This is
why:  The need to validate models that predict a lot of manmade warming
over the last 50 years that hasn't shown up.  Scientists will tell you
that they have fixed these problems, but we skeptics are fairly certain they have done it by adding artificial
fudge factors of dubious scientific merit  (I will confess to my embarassment that I have done exactly this when I have created industry models for a consulting client).

But one can also answer these questions about positive feedback loops from a
broader perspective.  Positive feedback loops are not unknown in nature
but are much rarer than negative feedback loops.  The reason is that
positive feedback loops lead to runaway processes that we seldom see in
nature.  Atomic fission is one of these thankfully rare process, and one can see that it is
probably lucky our universe is not populated with many such positive feedback
processes.  In our daily lives, we generally deal with negative
feedback:  inertia, wind resistance, friction are all negative feedback
processes.  If one knew nothing else, and had to guess if a natural
process was governed by negative or positive feedback, Occam's razor would say
bet on negative.  So, what about climate?  The evidence is equivocal,
but to be fair there is an example in our near universe of a runaway global
warming event - on Venus - though it occurred for reasons very different than
we are discussing with man-made climate change.

Negatives (and Positives) of Warming: While I have some trouble with
the science employed by global warming activists up to this point, it is on the
topic of the effects of global warming that the science really gets
flaky.  Now, certain effects are fairly likely.  For example,
hurricane activity will likely increase with warmer ocean temperatures.
Warmer ocean temperatures will also cause sea levels to rise, even without ice
melting, due to thermal expansion of the water.  And ice will melt, though
there is a really broad range of forecasts.

One reason that the ice
melting forecasts are hard
is because while me may talk about the world
warming a degree, the world does not warm evenly.  Most climate models
show the most warming on dry winter nights  (Siberian winters, for
example, get a disproportionate share of the warming).  An extra summer
degree in Arizona would suck; an
extra winter degree in Siberia would probably be
welcomed, and would likely extend growing seasons.

And it is here that you get the greatest silence from warming
fanatics.  Because
it should be self-evident that warming can be good and bad
.  Warming
can raise ocean levels and lead to droughts.  It can also extend growing
seasons and increase rain.  It all depends on where you are and what
forecast you are using.  The only common denominator is that most official
warming reports, such as those from the UN, spend an inordinate amount of time
discussing the negatives and very little time, if any, mentioning positive
offsets.  One of the reasons for this is that there is a culture in which
every environmental activist has been steeped in for years -- that man always
ruins nature.  That everything man does is bad.  Growth is bad.
Technology is bad.  To be fair, its not that many environmental scientists
are hiding the positive offsets, it's that they have been programmed for years to be
unable to recognize or acknowledge them.

Shouldn't We Fix it, Just to Be Safe:  If you get beyond the
hard core of near religious believers in the massive warming scenarios, the
average global warming supporter would answer this post by saying:
"Yes there is a lot of uncertainty, but you said it yourself: 
Though the doomsday warming scenarios via positive feedback in the climate
can't be proven, they are so bad that we need to cut back on CO2 production
just to be safe."

This would be a perfectly reasonable approach if cutting back on CO2
production was nearly cost-free.  But it is not.  The burning of
hydrocarbons that create CO2 is an entrenched part of our lives and our economies.
Forty years ago we might have had an easier time of it, as we were on a path to dramatically cut back on CO2 production
via what is still the only viable technology to massively replace fossil fuel
consumption -- nuclear power.  Ironically, it was environmentalists that
shut down this effort, and power industries around the world replaced capacity
that would have gone nuclear mostly with coal, the worst fossil fuel in terms
of CO2 production (per btu of power, Nuclear and hydrogen produce no CO2,
natural gas produces some, gasoline produces more, and coal produces the most).

Just halting CO2 production at current levels (not even rolling it back)
would knock several points off of world economic growth.  Every point of
economic growth you knock off guarantees you that you will get more poverty,
more disease, more early death.  If you could, politically, even
make such a freeze stick, you would lock China and India,
nearly 2 billion people, into continued poverty just when they were about to
escape it.  You would in the process make the world less secure, because
growing wealth is always the best way to maintain peace.  Right now, China can become wealthier from peaceful internal growth than it can from trying to loot
its neighbors.  But in a zero sum world created by a CO2 freeze, countries
like China would have much more incentive to create trouble outside its borders.  This
tradeoff is often referred to as a cooler but poorer world vs. a richer but
warmer world.  Its not at all clear which is better.

One final  statement:  I have lost trust in the scientific
community on this.  There are just too many statements floating around like
this one
that make it clear that getting people converted to the global
warming cause is more important than getting the science right.  Mann's
refusal to share his data so that his results can be validated (or invalidated,
as seems more likely now), the refusal
to consider any dissenting views
in its "scientific" conferences,
the sloppy
uncovered, the willingness to absurdly blame
every natural event on global warming
  -- all these create the
impression that global warming is a religion with doctrines that can't be
questioned, rather than what it actually is -- a really, really chaotic and complex area
of science we have only just begun to understand.

For other reading, probably the first place to look is the Skeptical Environmentalist by Bjorn
. Lomborg in this book has probably the best counter-case to the
enviro-disaster stories filling the media. He has become an object of absolute
hatred among the anti-growth anti globalization fanatics who have latched onto climate
change as the key to advancing their anti-technology and anti-capitalist
political agenda. The attacks on him have become nearly as edifying about what
drives the environmental movement as his book itself. The Economist has
a nice article about his book and about the wild-eyed furious reaction of
environmental activists to it. The Economist also editorializes
, and you can follow all the criticism and response here on Lomborg's site.

The site is
invaluable, in fact with a better compendium of data on climate than most
climate sites.  A good
place to start is this article

Other sources: This paper is
a good roundup of all the issues I have addressed. Cato has a lot of other
material here
as does the Heartland
and at The
  A great post from Silflay Hraka that is much more eloquent
(and concise) than I am is linked here.

Update:  I have published a (free) more comprehensive guide to the skeptics