It is very much worth checking out an item on Real Climate, from two Dutch scientists. They have found a paper by James Hansen and others from 1981, before climate change was even an occasion for political disagreement.

Hansen is now famous in the world of climate studies, and infamous to the world of the right wing, but back then he was a 40-year-old researcher who came up with a projection of how rising CO2 levels might affect global temperatures. Science lives for the "falsifiable hypothesis" -- a claim that can be tested against the evidence -- and that is what the paper by Hansen and his colleagues offered up. Three decades later, his worst-case projections were matched against what has happened since then. You should read their full findings, but this gives you the idea:

As the Dutch scientists say at the end of their Real Climate post:



To conclude, a projection from 1981 for rising temperatures in a major science journal, at a time that the temperature rise was not yet obvious in the observations, has been found to agree well with the observations since then, underestimating the observed trend by about 30%... It is also a nice example of a statement based on theory that could be falsified and up to now has withstood the test. The "global warming hypothesis" has been developed according to the principles of sound science.

Reading this cannot make you feel good about our current politics. (Thanks to EG for the tip.)