Climate scientists are often portrayed as alarmists by deniers, with the Intergovernmental Panel on Climate Change, or the IPCC, derided by naysayers. But a new review in the journal Global Environmental Change highlights a reality that most scientists already know: over the past 20 years the IPCC has underestimated climate change impacts.
Every five years, give or take, thousands of experts from more than 120 countries write an IPCC Report detailing the latest climate science.
Authors of the Global Environmental Change paper suggest climate scientists err on the conservative side because of traditional scientific culture values, “objectivity, skepticism, rationality, dispassion, and moderation.” The team, which included science historian Naomi Oreskes, found all of the IPCC’s measurable predictions were either accurate or conservative. None erred on the side of alarmism.
Prime examples are loss of Arctic sea ice and sea level rise. The last IPCC report estimated the Arctic would retain its summer ice until at least 2070. But melt has occurred at a much faster pace, with loss expected within the next 20 years.
This, in turn, has altered sea level rise. In its 2003 report, the IPCC predicted a rise of less than 2mm a year. But between 1993-2006 our oceans actually rose 50% more than the IPCC’s projections—a real concern for coastal areas.
Down playing climate impacts is not without cost. It could leave policymakers dragging their feet on the adaptation and the mitigation truly needed.
Web Links
Climate Central
http://www.climatecentral.org/news/report-ipcc-underestimate-assessing-climate-risks-15338
The Daily Climate
http://wwwp.dailyclimate.org/tdc-newsroom/2012/12/ipcc-climate-predictions
Mother Jones
http://www.motherjones.com/blue-marble/2012/12/report-ipcc-underestimating-climate-threat
Scientific American
Photo, taken on September 1, 2009, courtesy of the U.S. Geological Survey via Flickr.