I thought this article was outstanding, definitely worth reading the whole thing. It provides 10 well-considered arguments against
7. The CO2 cannot, from a scientific perspective, be the cause of significant global temperature changes:I'd never considered looking at the behavior of CO2 before.
The CO2 molecule is a linear molecule and thus only has limited natural vibrational frequencies, which in turn give this molecule only limited capability of absorbing radiation that is radiated from the Earth’s surface. The three main wavelengths that can be absorbed by CO2 are 4.26 micrometers, 7.2 micrometers, and 15.0 micrometers. Of those 3, only the 15-micrometer is significant because it falls right in range of the infrared frequencies emitted by Earth. However, the H2O molecule which is much more prevalent in the Earth’s atmosphere, and which is a bend molecule, thus having many more vibrational modes, absorbs many more frequencies emitted by the Earth, including to some extent the radiation absorbed by CO2. It turns out that between water vapor and CO2, nearly all of the radiation that can be absorbed by CO2 is already being absorbed. Thus increasing the CO2 levels should have very minimal impact on the atmosphere’s ability to retain heat radiated from the Earth. That explains why there appears to be a very weak correlation at best between CO2 levels and global temperatures and why after the CO2 levels have increased by 40% since the beginning of the industrial revolution the global average temperature has increased only 0.8 degrees centigrade, even if we want to contribute all of that increase to atmospheric CO2 increases and none of it to natural causes.
7 comments:
As a bit of a reality check, by his argument we would expect the surface of Venus to be around 150 - 200 F (which is what most people thought it would be when I was a kid). But, instead it turns out to be more like 600 F, hotter than Mercury. Maybe you should consider why his argument fails so very badly for Venus.
That's no answer at all. CO2 isn't the most complicated of molecules and it really doesn't do all that much.
And if CO2 is the big villain, why didn't global temps rise 1940-1980 when CO2 was shooting up?
Frankly, the whole thing seems to me like a symbiotic relationship between politicians and the research community with a good dose of that old-time religion thrown in.
So why is it that, although the Venusian atmosphere is 96.5% CO2 (along with 3.5% N2, 150 ppm SO2, 75 ppm Ar, and very little else), this gas that "really doesn't do all that much" managed to change a planet that could have been merely tropical into a roasted, dessicated hell-hole hot enough to melt zinc?
What van Biesen missed in the article you linked to, is that all he was considering was whether every IR photon emitted from the Earth's surface would be absorbed *once*. The thing is, it doesn't end there. The CO2 that absorbed the energy then re-emits it as IR in some random direction - maybe up towards space, and maybe down towards the ground. If it goes down, it has to start all over again working its way towards space, and if it goes up it may escape into space, or it may get re-absorbed and re-radiated. As the distance the energy travels before getting re-absorbed gets shorter, it turns into more of a random-walk to get out of the atmosphere, and more energy ends up tied up in the air. Venus is admittedly an extreme case, but it does pretty clearly demonstrate that adding more CO2 continues making things hotter and hotter, there isn't a "saturation" point. At least, not at low enough CO2 levels to do us any good.
The thing is, I first heard van Biesen's argument #7 way back in the 1990s. I thought it was convincing then, until I learned more about the mechanism and realized why it was wrong. For him to be re-presenting this argument roughly 20 years later as if it is something that somehow nobody though of before, he either needs to be willfully ignorant, or intentionally misleading. Which raises severe doubts about everything else he writes. Especially since he doesn't cite or link to any of his sources, so we can't tell whether he is accuratly reporting numbers, cherry-picking numbers that he can "spin", or even just making them up out of whole cloth.
For example, his "why didn't global temps rise 1940-1980 when CO2 was shooting up?" is leaving out the point that, at the same time, power plants were emitting large quantities of SO2, which makes highly-reflective sulfuric acid aerosols that reflect sunlight and have a cooling effect. And these SO2 aerosols began to decline in the 1980s due to widespread adoption of sulfur scrubbers[1]. Even Peter Watts, of "Watt's Up with That?" fame, agrees that sulfur dioxide emissions have a cooling effect and that their reduction in the 80s is what allowed temperatures to start rising then.
I've said this before, but it bears repeating: if you want to argue that trying to reduce CO2 in the atmosphere will be more expensive than just living with and adapting to the consequences, that's a perfectly defensible position. But arguing that there aren't going to *be* consequences strikes me as being just as irresponsible as claiming that the government can keep running up the debt forever without consequences.
[1] The adoption of sulfur scrubbers is something I am familiar with. I was working in coal desulfurization at the time.
Tim,
Are you saying that the national standards for SO2 are too low?
The national standard is 75ppb and we are currently around 25ppb (http://www3.epa.gov/airtrends/sulfur.html).
It looks like the 1980 level was 340ppb, which has been reduced by more than 10 fold.
Are you saying that this is similar to the salt debacle, where in salt intake in our diets was underestimated to the extreme? This lead to the reemergence of goiters (due to iodine deficiency - per iodized table salt), thyroid disease and hyponatremia.
Well, I'm not saying SO2 is "too low", since putting SO2 in the air has some other fairly obvious noxious effects. But yes, I am saying that changes have consequences that may not be the ones you expect, and making a change and then denying that it has consequences is irresponsible.
Ayup. Water vapor is just as strong a greenhouse gas as CO2. And there is about 100 times as much water vapor in the atmosphere as there is CO2. The radiative heat balance of the earth is controlled by the water vapor. There just ain't enough CO2 to make any difference. And on a planet where 3/4 of the surface is open water, you are gonna have a lot of evaporation to keep the water vapor content of the atmosphere high.
Tim, I really appreciate your comments. As soon as I typed the "CO2 doesn't do much" bit, I knew it was wrong as I was dismissing it's reactive possibilities. I left it up there because I knew a good response would be forthcoming. I didn't know about the SO2 data.
Still, I'm unconvinced about the whole thing. All I can see is one Doomsday scenario deadline pass after another with nothing happening.
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