Friday, May 29, 2009

Carbon from tea kettles

How much carbon do you emit per day? A ton per day or a ton per year? That's one of the problems I have with all of this talk about carbon -- few laypeople have any idea how much carbon they produce.

Everyone knows how much gasoline they put into their car how often, however, but nonetheless we seem to be switching to a system of carbon emissions. I suppose people got tired of hearing that they had to improve fuel consumption. Now, we get to deal with something more abstract -- something we cannot understand as well because we do not actually purchase carbon and do not actually see it when we produce it.

The problem with carbon emissions from cars is that we are essentially counting fuel consumption; carbon emissions go hand-in-hand with greater gasoline consumption. If we had a "carbon scrubber" that would remove carbon from the exhaust pipe (God only knows what would happen to it then -- would it be dropped off in little sugar-cube-size packets on the side of the road?), then we could truly say that we are reducing carbon without reducing fuel consumption, so it would make sense to count carbon emissions from cars rather than fuel economy. But there is no such thing as a carbon scrubber for cars, so counting carbon emissions instead of gas mileage makes no sense.

I am brought to this topic because of an article in Die Zeit about what the future will look like without economic growth. The article is really fantastic; I have never seen such a succinct synopsis of all of the imperatives for economic growth before, and the presentation allows the author to show the real challenges ahead of us if the age of economic growth is truly over. The author writes, listing the conventional wisdom he wishes to debunk, that we need economic growth because:

  1. Economic growth leads to prosperity and therefore greater happiness
  2. We need economic growth to create jobs (I love this sentence: "Einst war der Kapitalismus ein großer Wohlstandserzeuger, heute ist er, zumindest in den Industrieländern, eine große Arbeitsbeschaffungsmaßnahme." [Capitalism was once a great generator of prosperity, but today, at least in industrialized nations, it is a major job creation program.])
  3. At the microeconomic level, companies themselves need to grow because they have borrowed capital at interest, and they cannot pay the interest without posting greater returns, which leads to number four:
  4. At the macroeconomic level, countries need to grow; they do so simply as a result of number three.
It is interesting to see how the concept of what the French have been calling "décroissance" for some two decades now and other Vanguard economists have called "de-growth" in English is now entering the foreground. As the article in Die Zeit shows, we desperately need economists who can come up with viable solutions that do without constant growth.

Now back to carbon: unfortunately, the Zeit author uses some pretty bizarre figures in illustrating his case (this is my translation, parts left out for brevity are marked with an ellipsis):

People have been working on solar cars for decades, and there is no indication that they will be able to replace gasoline cars.... The Internet already produces more carbon emissions than the entire airline industry.... A single query at a large search engine consumes as much energy as a 60-watt light bulb left on for an hour.

It is unfortunate that the author uses such weak arguments in an otherwise spectacular article. I consider myself a solar insider, and I can tell you that I have never met anyone who believes that solar cars are going to replace combustion engines ever. It's not because solar does not work, but because electricity cannot be stored as easily as gasoline, and you cannot recharge batteries as fast as you can refill your gas tank. So let's be fair: we are not going to have solar cars or nuclear cars anytime soon because electricity does not work as well for motive transport.

I then tried to figure out how much electricity that search query uses. I found this blog entry citing a number of sources from 2007, but the figures are much different there: an 11-watt lightbulb running for one hour -- less than a fifth of the figures cited above. That blog entry references another article in German, which actually debunks the idea that the Internet consumes more energy than the airline industry.

I'm not going to pretend to be able to calculate how much energy a Google search consumes, but I was able to calculate how much electricity we are talking about based on the figure from Die Zeit, which seems unrealistic once you do the math. First, I tried to find how many searches Google handles per day, and the figures on the web vary widely -- from "1,200 million" to 293 million; I'll use the latter figure because it is more recent (from March 2009) and probably more conservative (note the US flag as the favicon ;-)).

At 60 watt-hours per search, that would mean that Google searches consume 6416.7 gigawatt-hours of electricity per year -- roughly 12 times the electricity consumed in Germany in one year. In fact, that is even more electricity than is consumed in the United States. How feasible is it that Google searches consume that much electricity?

Incidentally, it is interesting to see how cultural factors play into these assessments: the British talk about two Google searches needing the same amount of carbon as a kettle of tea. Of course, not even that is accurate because all of these figures are based on our general electricity figures. If we switch to 100 percent renewables, those figures drop considerably. Petite Planète has been running on 100 percent renewable electricity since 2003.

1 comment:

  1. All I needed to know is, how often do we need to repace tea kettles.