A new draft paper by James Hansen of NASA titled, “Paleoclimate Implications for Human-Made Climate Change” has been submitted for publication in the Belgrade Milankovitch Symposium volume — the paper is now under review, and part of it is below.  His message in the introduction is clear — Climate change will develop into the biggest issue of this century.  We have the opportunity to address it now, but the government is not doing that.  In fact, President Obama wrote a bizarre article for the Wall Street Journal stating that his administration will review all government regulations and get rid of those that hurt jobs or place some kind of “burden” on business.  He’s after “outdated regulations that stifle job creation and make our economy less competitive.” It’s bizarre because of the timing — at the exact moment that the EPA is going to take over greenhouse gas emission regulation because the Congress won’t.  Obama certainly knows that Republicans are already trying to destroy EPA regulations before they start.  Yet he purposely calls out the EPA for bad regulations in the article. The EPA is going to regulate carbon emissions and our president is promising Republicans that he’ll get rid of business-harming regulations. My guess is he means well, but this is going to come back to haunt his EPA. The Republicans will attempt to use his promise to try to halt EPA regulations.  Grit TV talks about it here.

*The video version of this commentary says twenty-two deaths—it is actually twenty-nine.

Hansen’s paper Abstract and Intro  is partially reprinted below, and you can download the entire paper here.

Paleoclimate Implications for Human-Made Climate Change

by James Hansen

ABSTRACT

Milankovic climate oscillations help define climate sensitivity and assess potential human-made climate effects. We conclude that Earth in the warmest interglacial periods was less than 1°C warmer than in the Holocene and that goals of limiting human-made warming to 2°C and CO2 to 450 ppm are prescriptions for disaster.

Polar warmth in prior interglacials and the Pliocene does not imply that a significant cushion remains between today’s climate and dangerous warming, rather that Earth today is poised to experience strong amplifying polar feedbacks in response to moderate additional warming. Deglaciation, disintegration of ice sheets, is nonlinear, spurred by amplifying feedbacks. If warming reaches a level that forces deglaciation, the rate of sea level rise will depend on the doubling time for ice sheet mass loss. Gravity satellite data, although too brief to be conclusive, are consistent with a doubling time of 10 years or less, implying the possibility of multi-meter sea level rise this century. The emerging shift to accelerating ice sheet mass loss supports our conclusion that Earth’s temperature has returned to at least the Holocene maximum. Rapid reduction of fossil fuel emissions is required for humanity to succeed in preserving a planet resembling the one on which civilization developed.

?1. Introduction
Climate change [...]