How does the climate science community account for a discrepancy in the ice core samples? ?
It’s a timescale issue. The 10 C increase didn’t happen over 30 years, or even 300 years. The entire 10 C warming at the end of an ice age takes several thousand years. The initial increase that is not CO2-driven (the first 800 years) is only a small part of total time the planet is warming. I believe that Jeff Severinghaus explains this as well in the realclimate article, if you are reading the one I am thinking about. Anyway, the point is that we haven’t had enough time yet to see the full impact of adding 80 ppm of CO2 because of the thermal lag of the oceans. As far as sensitivity goes, of the things that climate physicists know provide forcings for climate (e.g., solar, orbital dynamics, greenhouse gases), only greenhouse gases are providing a forcing large enough to cause the observed increase in temperature over the last 30 years. That doesn’t mean there couldn’t be other things at work, but climate physicists are fairly well convinced they know the first-order effects, and none
