Past and Current AAAS Leaders Aid Climate Change Report for United Nations

John Holdren
[Photo © Martha Stewart]

An elite panel of scientists, including several current and past AAAS officers, has outlined an ambitious roadmap for the United Nations to head off the worst climate changes and adapt to those that can no longer be avoided.

The report, requested by the U.N. and sponsored by the private United Nations Foundation and Sigma Xi, the Scientific Research Society, warns that society faces two starkly different futures. The current use of heat-trapping gases will lead to "increasingly serious climate-change impacts," it says, while the other path will "reduce dangerous emissions, create economic opportunity, help to reduce global poverty, reduce degradation of and carbon emissions from ecosystems," and contribute to sustainability.

It urges leadership at all levels of society, saying "there is no more time for delay."

The report was written by the 18-member Scientific Expert Group on Climate Change and Sustainable Development, which includes three past and current AAAS leaders: AAAS Board Chairman John P. Holdren; former AAAS President and Chairman Peter H. Raven, director of the Missouri Botanical Garden; and former AAAS Board Member Rosina Bierbaum, dean of the University of Michigan's School of Natural Resources and Environment. Raven and Bierbaum co-chaired the Expert Group.

Rosina Bierbaum

"Our report makes clear that the challenge before us is to reduce the risk of climate change resulting in intolerable global impacts,"

Raven said in a news release issued by the U.N. Foundation and Sigma Xi on 27 February.

"It is still possible to avoid an unmanageable degree of climate change, but the time for action is now," said Holdren, director of the Woods Hole Research Center and the Teresa and John Heinz Professor of Environmental Policy at Harvard University.

Peter H. Raven

"The global-average surface temperature has already risen about 0.8°C above pre-industrial levels and is projected to rise another 2-4°C by 2100 if CO² emissions and concentrations grow according to mid-range projections," added Holdren, a lead author of the report. "Prudence dictates limiting the average temperature increase to no more than 2-2.5°C above the pre-industrial level, and our report offers clear recommendations for achieving that goal."

Measures already exist, the report says, for reducing heat-trapping greenhouse gas emissions. It recommends immediate steps to upgrade vehicle fuel efficiency, improve energy use through advanced designs in commercial and residential buildings, expand the use of biofuels and build coal-fired power plants that can affordably capture and sequester heat-trapping carbon dioxide gas.

The report also outlines steps to adapt to changes that cannot be avoided. Even if greenhouse emissions from human activity could be instantly stopped, it says, the world would not escape further climate change. The immense mass of the world's oceans responds slowly to warming air temperatures. Because of such thermal inertia in the oceans, the impact of today's warming could be felt for several decades to come.

Among the report's adaptation recommendations: more investment in ventilation, passive cooling and air conditioning; additional protection against floods; development of crop varieties that are more heat- and drought-resistant; increased storm protection for coastal areas and movement of populations from the most vulnerable coastal areas.

The 166-page report, two years in the making, also says the U.N. must better prepare to help millions of "environmental refugees" who could be forced to leave sensitive areas in the wake of severe climate change.

"The world is experiencing climate disruption now and the increases in droughts, floods, and sea level rise that will occur in the coming decades will cause enormous human suffering and economic losses," Bierbaum said. "The poorest are likely the most vulnerable. We imperil our children's and grandchildren's future if we fail to improve society's capacity to adapt to a changing climate."

The report, "Confronting Climate Change: Avoiding the Unmanageable and Managing the Unavoidable," was prepared as input for the upcoming meeting of the U.N.'s Commission for Sustainable Development.

Earl Lane

28 February 2007