Global warming denialism is still strong, particularly by those on the right for some reason. Perhaps it’s because they adhere to the idea that if we want to solve this problem, it’s going to hurt and we can’t have that happen. Of course, they’re wrong on that point. (Check out some of Amory Lovins’ work, for example.) They hate the answer, so they hate the theory. Never mind they’ve got the answer completely misconstrued–attacking a theory because you disagree with its result is not the way to go. You should be critical of the basis of the theory. Unfortunately, this is lacking in the “debate” on global warming.

Some in St. Cloud still seem to be fascinated with the subject after Bachmann’s recent “visit” to campus. This is good, but they’re still attacking the theory because they disagree with what it says, not the scientific basis for it. See, for example, this recent post by King Banaian, an SCSU economics professor and chairman of the department. There’s an interesting discussion taking place there, but let’s evaluate some of the claims.

The Earth’s climate is driven by the receipt and redistribution of solar energy. Despite this crucial relationship, the sun tends to be brushed aside as the most important driver of climate. Calculations on supercomputers are primitive compared with the complex dynamism of the Earth’s climate and ignore the crucial relationship between climate and solar energy.

Yes, of course; the sun is an important driver of climate, but it is not by any means the only driver. Greenhouse gases, for example, also play a crucial role in the climate. So it’s important to look at all the meaningful forcings. And, as it happens, scientists have. The journalist (no wonder) here is flatly incorrect; solar variation has been accounted for in the models. What we find is that solar irradiance had a radiative forcing of .12 W/m^2 (watts per square meter) in 2005. What this means is that it does have a positive radiative forcing (increases temperatures), but it is small, especially when we compare it to human activities (emitting CO2 and methane, land use, etc.), which has a radiative forcing of 1.6 W/m^2. So, clearly, human’s impact on climate is much more profound than that of solar variation.

“To reduce modern climate change to one variable, CO2, or a small proportion of one variable – human-induced CO2 – is not science. To try to predict the future based on just one variable (CO2) in extraordinarily complex natural systems is folly. Yet when astronomers have the temerity to show that climate is driven by solar activities rather than CO2 emissions, they are dismissed as dinosaurs undertaking the methods of old-fashioned science.”

Again, it’s not being reduced to one variable. Many are being accounted for, including solar variation. “Ah, but CO2 doesn’t account for much of the atmosphere, and certainly only a tiny amount is human-induced, so that can’t be the answer.” Wrong. It’s true that human-caused CO2 makes up a small amount of the atmosphere. But that’s not the point at all. Ice core data has shown that CO2 levels are higher now than they have been for at least 650,000 years; other evidence (see Pearson and Palmer, 2000, for example) suggests it may have been on the magnitude of 20 million years. The rise in CO2 and other greenhouse gases since the start of the Industrial Revolution is unambiguous. (And CO2 levels keep going up, and are expected to for a long time.) It’s important to keep in mind that CO2 has a long atmospheric lifetime (about 100 years–water vapor’s is about 10 days). So this means that humans are causing greenhouse gases to increase at a rate faster than carbon sinks can accommodate, which simply means temperature is going to rise. The radiative properties of greenhouses gases, known for over a 100 years now, explains this very well.

Over time, the history of CO2 content in the atmosphere has been far higher than at present for most of time. Atmospheric CO2 follows temperature rise. It does not create a temperature rise. CO2 is not a pollutant. Global warming and a high CO2 content bring prosperity and longer life.

I’ve addressed the “CO2 follows temperature rise” in an earlier post here. The argument that CO2 is not a pollutant and that increasing CO2 is actually a good thing are interesting ones. Given all the negative impacts that global warming is expected to bring or, indeed, has already brought about, it’s hard to imagine how CO2 increases could be beneficial. One argument is that plants love CO2, so production will increase. This is a seriously strained argument. New Scientist does a good enough job at debunking this myth.