I'm a San Francisco liberal. Nancy Pelosi is my representative and I will be voting for her in the next election. But, I'm skeptical about the catastrophic claims made by some regarding the effects of greenhouse gases. This weblog is about trying to make these two facts about myself cohere.
Climate change has become so politicized that it's almost impossible to state one's position simply--but I will try and do so here. Climate change catastrophists classify those who disagree with their position as 'deniers,' Republicans in bed with big oil, etc. Well, there's at least one exception. Here's what I believe regarding climate change:
1. The greenhouse effect is real.
2. CO2 is a greenhouse gas. Doubling CO2 from 280 to 560 parts per million will, in isolation, tend to raise the Earth's temperature by between 1 and 1.5 degrees C.
3. Some scientists postulate that increased CO2 will initiate a positive feedback cycle that will amplify the effect by causing, for example, water vapour, to retain more heat. These scientists fear that the amplification will cause the 1-1.5 degree increase to be more like 4-7 degrees.
4. This hypothesis regarding positive feedback has not been proven.
5. Evidence found so far seems to suggest that this hypothesis may not be true.
If I utter statement 4 in certain circles, I get in trouble quite quickly. If I dare to use statement 5, some think me mad.