Distribution of professional opinion on climate change

Paul Krugman highlighted a post by Joe Romm ‘Hug The Monster’: Why So Many Climate Scientists Have Stopped Downplaying the Climate Threat. Romm looks at why climate scientists are much more concerned in private than they are in public about the impact of global warming, although that is starting to change:

The piece helps dispel the myth that climate scientists have long been overhyping climate impacts — when everyone who actually follows climate science and talks to any significant number of climate scientists knows that the reverse is true. As Blakemore writes:

    Established scientists, community and government leaders and journalists, as they describe the disruptions, suffering and destruction that manmade global warming is already producing, with far worse in the offing if humanity doesn’t somehow control it, are starting to allow themselves publicly to use terms like “calamity,” “catastrophe”, and “risk to the collective civilization”….

Romm has the following graph in his article:

That's a truly frightening graph.

Romm also links to an other article he wrote An Illustrated Guide to the Science of Global Warming Impacts: How We Know Inaction Is the Gravest Threat Humanity Faces. In the article he has a chart from the Hadley Center:

Romm also has a chart from the National Center for Atmospheric Research showing the likely impact of climate change on droughts via the Palmer Drought Severity Index:

The PDSI [Palmer Drought Severity Index] in the Great Plains during the Dust Bowl apparently spiked very briefly to -6, but otherwise rarely exceeded -3 for the decade (see here).

    The large-scale pattern shown in Figure 11 [of which the figure above is part] appears to be a robust response to increased GHGs. This is very alarming because if the drying is anything resembling Figure 11, a very large population will be severely affected in the coming decades over the whole United States, southern Europe, Southeast Asia, Brazil, Chile, Australia, and most of Africa.

The National Center for Atmospheric Research notes “By the end of the century, many populated areas, including parts of the United States, could face readings in the range of -8 to -10, and much of the Mediterranean could fall to -15 to -20. Such readings would be almost unprecedented.”

For the record, the NCAR study merely models the IPCC’s “moderate” A1B scenario — atmospheric concentrations of CO2 around 520 ppm in 2050 and 700 in 2100.  We’re currently headed much higher by century’s end, but I’m sure with an aggressive program of energy R&D we could keep that to, say 800 ppm.

Things aren't looking good.