I've seen some ads on TV recently to the effect that "Carbon dioxide is not pollution", and the more aggressive claim, "CO2 is Green". Now, there's no doubt that this is a disingenuous attempt to poleaxe our legislative attempts to control greenhouse gases, sponsored by companies with bad intentions, bad faith, and bad science. Still, I think they have it at least half-right.
Carbon dioxide is a naturally-occurring gas. It is not a pollutant, something which irreversibly contaminates all it touches, like nuclear waste or coal mining tailings. If the carbon dioxide level in our atmosphere doubled, we wouldn't notice it in our breathing. For example, we can adapt to half the oxygen of sea level; we have that, and less, up here in Taos, and it takes about a day for almost anyone--except emphysema patients--to adapt.
Still, I'm far from a climate change denier. I see huge, though not civilization-ending, negative effects if current trends continue: Bangladesh--and other poor, low-lying countries--will be catastrophically affected by rising sea levels; supplies of water will have huge disruptions; ecosystems will be badly, and unpredictably, messed with; and it looks as though major storms' destructive powers are being multiplied. We do need to do something about it, and we have to provide mentorship and assistance to the poorer countries so they can do something, too: this is clearly a global issue.
I'm just not convinced that reducing greenhouse gas emissions are the only, or even necessarily the best, route to achieve these ends. Carbon dioxide, like water, has a cycle, in which animals and plants figure prominently. There are some plants that absorb more carbon dioxide than others; carbon dioxide is absorbed by the oceans (an effect which causes its own problems); carbon dioxide, unlike, say, nuclear waste, wouldn't need to be sequestered for tens of thousands of years: an approach which took CO2 out of the atmosphere for 500 years, after which it leaked slowly back in, would actually be kicking the can down the road effectively. I'm thinking that there may be chemical reactions between some minerals and CO2 that might prove to be an effective approach to taking CO2 out of the atmosphere, too.
The bottom line for me is that reducing CO2 and other greenhouse gases is moral, and the inverse is true, too. The goal is not to eliminate CO2, though--it's like sin, or poverty, or war, or disease. It's something that's going to be with us, and we should seek to ameliorate its harmful effects. There is more than one way to skin a cat, but we do need to remove at least some of its fur, and we need to study the science of doing it from several different directions.
So I support the 350 movement (the number is the desired parts per million of CO2 in the atmosphere; we're already above that level). I will do so with an ear conditioned by the more nuanced attitude to the gas that I've described.