The first independent review of the influential 2007 United Nations assessment on climate change has determined that despite some errors in the initial report, the overall findings were accurate. The Netherlands Environmental Assessment Agency (PBL) published its review on July 5th, highlighting sloppily presented evidence and making suggestions for reporting with greater transparency in the future but not disputing the scientific case for the existence of human-driven climate change.
In response to the discovery of inaccuracies in the Intergovernmental Panel on Climate Change’s most recent report, the environment minister in the Dutch parliament, Jacqueline Cramer, called on the PBL to review the IPCC’s 32 main conclusions on climate change’s regional effects. IPCC chair Rajendra Pachauri was forced to apologize in May for false claims in the 2007 report that Himalayan glaciers might all disappear by 2035. And the PBL itself was to blame for the report’s miswritten statement that 55% of the Netherlands is below sea level, when in reality, that figure refers to the percentage of the country prone to flooding. These mistakes have been used by deniers of climate science to discredit the entire 3,000-page report, which was lauded at the time of its release and earned its authors a Nobel Prize, shared with Al Gore.
The most significant blunder uncovered by the PBL’s review involved miscalculations about the number of people in Africa in danger of facing water shortages by 2020 due to increased droughts and other climactic shifts. The 2007 estimate was between 75 and 250 million people, whereas, it would have been more precise to have capped the figure at 220 million, according to the new evaluation. While acknowledging that a document of such density is bound to contain some questionable statements, the PBL also pointed to a tendency by the IPCC authors to generalize and to accentuate the negative elements contained in the report when assembling information for summaries.
Next month, the U.N.’s own independent panel of scientists will provide a second appraisal. Even if the consensus on climate change is unchanged after its release, as is anticipated, the discovery of such careless errors and typos in the first place serves as an important lesson as work begins on the fifth assessment report, which is scheduled for 2014. Maarten Hajer, the Dutch agency’s director, praised the IPCC’s work, calling it “formidable.” He said that although the organization’s most recent assessment might not be flawless, “it is the best we have, and the best we can aim for is to further improve it.”