How the IPCC Portrayed a Net Positive Impact of Climate Change as a Negative

18 09 2008

By Indur Goklany. Originally published at the Cato Institute, but published here also by invitation from the author.

Arguably the most influential graphic from the latest IPCC report is Figure SPM.2 from the IPCC WG 2’s Summary for Policy Makers (on the impacts, vulnerability and adaptation to climate change). This figure, titled “Key impacts as a function of increasing global average temperature change”, also appears as Figure SPM.7 and Figure 3.6 of the IPCC Synthesis Report (available at http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr.pdf). Versions also appear as Table 20.8 of the WG 2 report, and Table TS.3 in the WG 2 Technical Summary. Yet other versions are also available from the IPCC WG2’s Graphics Presentations & Speeches, as well as in the WG 2’s “official” Power Point presentations, e.g., the presentation at the UNFCCC in Bonn, May 2007 (available at http://www.ipcc.ch/graphics/pr-ar4-2007-05-briefing-bonn.htm).

Notably the SPMs, Technical Summary, Synthesis Report, and the versions made available as presentations are primarily for consumption by policy makers and other intelligent lay persons. As such, they are meant to be jargon-free, easy to understand, and should be designed to shed light rather than to mislead even as they stay faithful to the science.

Let’s focus on what Figure SPM.2 tells us about the impacts of climate change on water.

The third statement in the panel devoted to water impacts states, “Hundreds of millions of people exposed to increased water stress.” If one traces from whence this statement came, one is led to Arnell (2004). [Figure SPM.2 misidentifies one of the sources as Table 3.3 of the IPCC WG 2 report. It ought to be Table 3.2. ]

What is evident is that while this third statement is correct, Figure SPM.2 neglects to inform us that water stress could be reduced for many hundreds of millions more — see Table 10 from the original reference, Arnell (2004). As a result, the net global population at risk of water stress might actually be reduced. And, that is precisely what Table 9 from Arnell (2004) shows. In fact, by the 2080s the net global population at risk declines by up to 2.1 billion people (depending on which scenario one wants to emphasize)! Read the rest of this entry »


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Global Warming to Shake Up Big Ten

18 09 2008

Posted by John Goetz

Jim Nichols of the Cleveland Plain Dealer wrote an article this past Tuesday (September 16) that has gotten the attention of Ohio State and Michigan fans around the country:

Global warming could send buckeye trees to Michigan

Michigan may be coolest place for it to be

Jim’s article starts out:

Global-warming predictions can send a chill down one’s spine: Melting polar ice caps, more hurricanes, epidemics, coastal swamping, drought and economic catastrophe.

Add to that a new horror scenario: a veritable exodus of Ohio buckeye trees into Michigan.

Could “The Heart of It All” become “The Heat of it All” and the Wolverine State become – arguably – the relatively cooler place to be?

Indeed, a coalition of health, environmental and outdoors groups dubbed Save the Buckeye warned of this Friday.

“It’s kind of ironic that because of climate change, the Ohio buckeye could wind up being more at home in Michigan than it is in Ohio,” said Tom Bullock, a coalition spokesman.

Jim goes on to mention that “garish and ominous billboards” have been put up on the Ohio State campus as part of a public-education campaign in Columbus. These billboards are designed to put fear into both OSU and U of M fans: Read the rest of this entry »


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Categories : climate_change, fun_stuff, local_issues