Refining climate change risk
A new approach combines physical changes with socioeconomic factors to predict risks.
Last month's UN conference on climate change in Bali, Indonesia showed the difficulties faced in international negotiations to set binding limits for greenhouse gases. A missing component of these discussions, some researchers say, is an estimate of how a country's socioeconomic attributes affect its ability to adapt to climate change. A new study published December 10 in Proceedings of the National Academy of Sciences U.S.A. integrates physical risk with poverty, wealth, and population size to create a new "socioclimatic" risk for each nation.
Relatively moderate climate change is expected in China, India, and the U.S., according to the research team from Purdue University and the Abdus Salam International Centre for Theoretical Physics (Italy). Yet these three countries—which are not bound by the Kyoto treaty on climate change but are all considered major emitters of greenhouse gases—will face "substantial exposure relative to other nations."
Noah Diffenbaugh, assistant professor of earth and atmospheric sciences at Purdue, and the lead author of the study, said that when China's expected moderate physical changes are combined "with the fact that China has the second largest economy in the world, a substantial poverty rate, and a large population, it creates one of the largest combined exposures on the planet." The same holds true for the U.S., he said. Its large population means more lives are at stake, and climate-related damage to its extensive infrastructure would harm the economy.
When population is taken into account, the climate impacts on most African nations shrink, a surprising finding, the authors note. Instead, South and East Asia, including India and China, rise to the top of the list of the most exposed countries based on the interaction of poverty, climate changes, and population.
Michael Mastrandrea, a research associate with the Center for Environmental Science and Policy at Stanford University and a member of the Intergovernmental Panel on Climate Change, said that this approach provides a new method to assess climate change risks. "This paper proposes an interesting basis from which to quantify the broad implications of concurrent changes in climate and society," he said.
