http://www.economicsforaroundearth.com

With all good wishes,
Charles Pierce

Thanks, I feel much better now.

Solar evolution. Over long periods of time the sun does grow hotter. IIRC the current rate is estimated to be 6% per billion years. In the context of a few million years that is not significant. Over geologic time it is very significant. The early earth had to have had a strong greenhouse effect, otherwise it would have frozen over. In effect the amount of CO2 needed to keep the earths temperature within a reasonable (for life) range, gradually diminishes over time. Of course the sun won’t literally explode, but this rate of increase in brightness will gradually accelerate, until at maximum during the red giant phase, it will be thousands of times brighter than currently.

Interestingly the elliptical orbit has a first order effect which is zero! The reason is that the received intensity varies as inverse squared, and the angular rate of the earth in its orbit also varies as inverse squared. The total amount of radiation received during a season is independent of the phase angle in the elliptical orbit! So in the current configuration the northern hemisphere gets a short mild winter, and a long mild summer. Wait half a precession cycle, and we will have long severe winters, and short, but (more) severe summers. Of course these second order effects are important. At our current ellipticity, the January sun appears to be 7% more intense than the July sun. Exactly the opposite of the usual near/far answer people give.

The changes you cite would cause positive feedback – runaway cooling. Where’s the regulator?

I remember when the creationist’s mantra was “no missing link”. Then numerous “missing links” were found. Did they apologize and hang their heads? The IDers, maddeningly, embrace both guided evolution and no evolution, which are obviously different things, but they get to include the numbskull young earth creationists that way.