James Hansen's activity stream


  • published Isolation of 1600 Pennsylvania Avenue: Part I in Blog 2015-12-07 14:32:03 -0500

    Isolation of 1600 Pennsylvania Avenue: Part I

    James Hansen, 27 November 2015 — Earlier this year I received a message from a long-time reader of my Communications[1], who was persuaded of the urgency of the climate problem. As a significant supporter of the Democratic Party, he had the opportunity to meet President Obama, and he was preparing a specific question: would the President be willing to “meet with Jim Hansen”, who, the supporter asserted, understood the problem as well as anyone and has “some viable ways to fix the problem”?

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  • published Sea Levels in Blog 2015-07-27 14:11:08 -0400

    Multi-Meter Sea Level Rise already a Threat

    hansen-140923.jpgIt’s time to stop waffling so much and say that the evidence is pretty strong: multi-meter sea level rise is an issue for today’s public, not next millennium’s

    In 2005 I argued that ice sheets may be more vulnerable than IPCC (Intergovernmental Panel on Climate Change) estimated, mainly because of effects of a warming ocean in speeding ice melt.[1]  In 2007 I wrote “Scientific Reticence and Sea Level Rise”, describing and documenting a phenomenon that pressures scientists to minimize the danger of imminent sea level rise.[2]

    About then I became acquainted with remarkable studies of geologist Paul Hearty.  Hearty found strong evidence for sea level rise late in the Eemian to +6-9 m (20-30 feet) relative to today.  The Eemian is the prior interglacial period (~120,000 years ago), which was slightly warmer than the present interglacial period (the Holocene) in which civilization developed.  Hearty also found evidence for powerful storms in the North Atlantic near the end of the Eemian period.

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  • published Global Temperature in 2014 and 2015 in Blog 2015-01-16 12:52:22 -0500

    Global Temperature in 2014 and 2015

    James Hansen [a], Makiko Sato [a],[b], Reto Ruedy [c], Gavin A. Schmidt [b], Ken Lo [c]

    Abstract.  Global surface temperature in 2014 was +0.68°C (~1.2°F) warmer than the 1951-1980 base period in the GISTEMP analysis, making 2014 the warmest year in the period of instrumental data, but the difference from the prior warmest year (2010), less than 0.02°C, is within uncertainty of measurement.  The eastern two-thirds of the contiguous United States was persistently cool in 2014, cooler than the 1951-1980 average in all seasons.  Record warmth at a time of only marginal El Niño conditions confirms that there is no “hiatus” of global warming, only a moderate slowdown since 2000.  Global temperature in 2015 may further alter perceptions.  We discuss the prospects for the 2015 global temperature in view of the seeming waning of the current weak El Niño.

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  • published Assuring Real Progress on Climate in Blog 2014-12-24 11:56:55 -0500

    Assuring Real Progress on Climate

    In the “Lima Accord”, adopted a week ago in reasonably congenial negotiations in Peru, nearly 200 nations agreed to reduce their fossil fuel emissions from burning of coal, oil and gas.  Nations are to define their specific plans prior to a final agreement in Paris in December 2015.  No country will be legally bound to a specific reduction, but the hope is that peer pressure will result in both ambitious targets for the general good as well as good faith efforts at compliance.

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