Good Arguments and Bad Arguments About Climate Change

Spencer copyRoy Spencer, who was a senior scientist for climate studies at NASA for many years, author of The Great Global Warming Blunder, and one of the inventors of the satellites that now track global temperature data, has two very useful posts up at his website on bad and good arguments about climate change.  Being a scrupulous scientist, he is concerned when he hears critics with the right inclinations push bad arguments.  As he warns in his first post, “when skeptics embrace “science” that is worse that the IPCC’s science, we hurt our credibility.”  Here are a few excerpts from his two posts edited down for length, but you should red the whole thing if you have time and make a note of following his site:

1. THERE IS NO GREENHOUSE EFFECT. . . . Please stop the “no greenhouse effect” stuff. It’s making us skeptics look bad. I’ve blogged on this numerous times…maybe start here.

2. THE GREENHOUSE EFFECT VIOLATES THE 2ND LAW OF THERMODYNAMICS. The second law can be stated in several ways, but one way is that the net flow of energy must be from higher temperature to lower temperature. This is not violated by the greenhouse effect. . .

3. CO2 CANT CAUSE WARMING BECAUSE CO2 EMITS IR AS FAST AS IT ABSORBS. No. When a CO2 molecule absorbs an IR photon, the mean free path within the atmosphere is so short that the molecule gives up its energy to surrounding molecules before it can (on average) emit an IR photon in its temporarily excited state. See more here. Also important is the fact that the rate at which a CO2 molecule absorbs IR is mostly independent of temperature, but the rate at which it emits IR increases strongly with temperature. . .

4. CO2 COOLS, NOT WARMS, THE ATMOSPHERE. This one is a little more subtle because the net effect of greenhouse gases is to cool the upper atmosphere, and warm the lower atmosphere, compared to if no greenhouse gases were present. Since any IR absorber is also an IR emitter, a CO2 molecule can both cool and warm, because it both absorbs and emits IR photons.

5. ADDING CO2 TO THE ATMOSPHERE HAS NO EFFECT BECAUSE THE CO2 ABSORPTION BANDS ARE ALREADY 100% OPAQUE. First, no they are not, and that’s because of pressure broadening. Second, even if the atmosphere was 100% opaque, it doesn’t matter. Here’s why.

6. LOWER ATMOSPHERIC WARMTH IS DUE TO THE LAPSE RATE/ADIABATIC COMPRESSION. No, the lapse rate describes how the temperature of a parcel of air changes from adiabatic compression/expansion of air as it sinks/rises. . . More about all this here.

7. WARMING CAUSES CO2 TO RISE, NOT THE OTHER WAY AROUND The rate of rise in atmospheric CO2 is currently 2 ppm/yr, a rate which is 100 times as fast as any time in the 300,000 year Vostok ice core record. And we know our consumption of fossil fuels is emitting CO2 200 times as fast! So, where is the 100x as fast rise in today’s temperature causing this CO2 rise? C’mon people, think. But not to worry…CO2 is the elixir of life…let’s embrace more of it!

8. THE IPCC MODELS ARE FOR A FLAT EARTH I have no explanation where this little tidbit of misinformation comes from. Climate models address a spherical, rotating, Earth with a day-night (diurnal) cycle in solar illumination and atmospheric Coriolis force (due to both Earth curvature and rotation). Yes, you can do a global average of energy flows and show them in a flat-earth cartoon, like the Kiehl-Trenberth energy budget diagram which is a useful learning tool, but I hope most thinking people can distinguish between a handful of global-average average numbers in a conceptual diagram, and a full-blown 3D global climate model.

9. THERE IS NO SUCH THING AS A GLOBAL AVERAGE TEMPERATURE Really?! Is there an average temperature of your bathtub full of water? Or of a room in your house? Now, we might argue over how to do the averaging (Spatial? Mass-weighted?), but you can compute an average, and you can monitor it over time, and see if it changes. . .

10. THE EARTH ISN’T A BLACK BODY. Well, duh. No one said it was. In the broadband IR, though, it’s close to a blackbody, with an average emissivity of around 0.95. But whether a climate model uses 0.95 or 1.0 for surface emissivity isn’t going to change the conclusions we make about the sensitivity of the climate system to increasing carbon dioxide.

And here are Spencer’s 10 good reasons for being a skeptic:

1) No Recent Warming. If global warming science is so “settled”, why did global warming stop 15 years ago, contrary to all “consensus” predictions?

2) Natural or Manmade? If we don’t know how much of recent warming is natural, then how can we know how much is manmade?

3) IPCC Politics and Beliefs. Why does it take a political body (the IPCC) to tell us what scientists “believe”? And when did scientists’ “beliefs” translate into proof? And when was scientific truth determined by a vote…especially when those allowed to vote are from the Global Warming Believers Party?

4) Climate Models Can’t Even Hindcast How did climate modelers, who already knew the answer, still fail to explain the lack of a significant temperature rise over the last 30+ years? In other words, how to you botch a hindcast?

5) …But We Should Believe Model Forecasts? Why should we believe model predictions of the future, when they can’t even explain the past?

6) Modelers Lie About Their “Physics”. Why do modelers insist their models are based upon established physics, but then hide the fact that the strong warming their models produce is actually based upon very uncertain “fudge factor” tuning?

7) Is Warming Even Bad? Who decided that a small amount of warming is necessarily a bad thing?

8) Is CO2 Bad? How did carbon dioxide, necessary for life on Earth and only 4 parts in 10,000 of our atmosphere, get rebranded as some sort of dangerous gas?

9) Do We Look that Stupid? How do scientists expect to be taken seriously when their “theory” is supported by both floods AND droughts? Too much snow AND too little snow?

10) Selective Pseudo-Explanations. How can scientists claim that the Medieval Warm Period (which lasted hundreds of years), was just a regional fluke…yet claim the single-summer (2003) heat wave in Europe had global significance?



Books to read from Power Line