Friday, April 06, 2007

One inch forward, ten feet backward.

Bush has gone from distancing himself from measures of global warming to trying to make pacts with Brazil and China to share technology. As many pointed out gleefully when Gore tried it, such carbon offsets mean little with no cap and trade system in place - but he was no longer ignoring the problem.

The National Review Online was kind enough to print a transcript of a Fred Thompson radio broadcast, so we know what we'll get if the Republicans nominate and get him elected.

Some people think that our planet is suffering from a fever. Now scientists are telling us that Mars is experiencing its own planetary warming: Martian warming. It seems scientists have noticed recently that quite a few planets in our solar system seem to be heating up a bit, including Pluto.

He doesn't actually say none are cooling - or give a percentage. Never mind that. The best way to decide if solar radiation is causing warming is probably to observe the sun. Gristmill is an environmental site - but they include links to the original research.

This is a job for satellites. According to PMOD at the World Radiation Center there has been no increase in solar irradiance since at least 1978, when satellite observations began. This means that for the last thirty years, while the temperature has been rising fastest, the sun has not changed.

There has been work done reconstructing the solar irradiance record over the last century, before satellites were available. According to the Max Planck Institute, where this work is being done, there has been no increase in solar irradiance since around 1940. This reconstruction does show an increase in the first part of the 20th century, which coincides with the warming from around 1900 until the 1940s. It's not enough to explain all the warming from those years, but it is responsible for a large portion. See this chart of observed temperature, modeled temperature, and variations in the major forcings that contributed to 20th century climate.

Now let's ask - suppose we keep increasing our production of greenhouse gases - and the sun begins to warm again. Meanwhile, tell me if you find an alternative reading of these two sets of data from global warming 'skeptics', or if they merely repeat that the sun has warmed over much longer periods.

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