An international committee of hundreds of top scientists produced a gloomy forecast this month for how humans and natural ecosystems will fare in the future, as the effects of global warming intensify. “No one of us will escape the impacts of a warming planet,” said Patricia Romero Lankao, a researcher at the National Center for Atmospheric Research, during a conference call from Brussels, where she was taking part in writing the committee’s report.
The Intergovernmental Panel on Climate Change, an arm of the United Nations, said that warming would create some winners and losers in the near term. For example, parts of the United States could see crop yields climb in the next few decades with modest increases in temperatures. At the same time, however, residents of cities will suffer more health problems from longer, hotter heat waves that worsen pollution. Warming is also expected to expand the range of pests and dry out forests in the summer, leading to more fires.
As the warming continues, the negative consequences will grow in magnitude around the world, the panel concluded in its 23-page summary for policy makers. The full report on the impacts of climate change is expected later this year. This is the second of four reports the panel will issue this year.
Bitter Predictions
In general, global warming will enhance disparities between nations. The higher latitudes, where much of the world’s wealth is accumulated, will receive more rainfall. But water availability will decline by 10 percent to 30 percent over the same time in already-dry spots such as the American Southwest, Asia, Latin America and much of Africa.
“People in developing countries — one example is sub-Saharan Africa — who have contributed the least to the atmospheric buildup of greenhouse gases will be hardest hit by climate change,” said Ms. Romero Lankao. By the year 2020, warming in Africa could cut crop production in half in some countries, according to the report.
But the wealthiest continents will also suffer as the world warms. Water problems will intensify in parts of Australia. Europe will face more frequent inland and coastal flooding. “We learned from the heat wave in Europe that claimed thousands of lives that a natural disaster can overwhelm a number of countries at once even if they are wealthy,” said Ms. Romero Lankao.
Jonathan Patz, an associate professor of environmental studies at the University of Wisconsin at Madison, who also helped write the panel’s report, said that “climate change presents one of the most challenging environmental public-health threats of this century.” The additional heat waves and altered wind patterns could lead to more ozone pollution in parts of the United States. The warmer climate will cause pollen levels to surge and could enhance the severity of outbreaks of the West Nile virus in the United States.
Hunger Exacerbated
In some parts of the world, the expected changes will exacerbate rates of hunger and malnutrition, he said. James L. Connaughton, chairman of the White House Council on Environmental Quality, said in a conference call that the panel’s report “underscores what the president has been saying for a long time about the seriousness of the challenge.”
In his State of the Union address this year, President Bush pledged to replace 20 percent of the United States’ petroleum usage with biofuels by the year 2020.
But environmentalists have criticized the Bush administration for resisting efforts to cut greenhouse-gas emissions, and, according to Ms. Romero Lankao, for playing down some of the panel’s conclusions. Although scientists wrote the draft of the climate report, the panel’s rules call for the final language to be approved by officials from the more than 100 nations that are members of the panel. The U.S. representatives, along with those from a few other countries, said Ms. Romero Lankao, fought successfully to remove language stating that scientists were quite confident that climate change has already caused noticeable impacts. “We couldn’t write that our level of certainty was very high,” she said.
http://chronicle.com Section: Research & Publishing Volume 53, Issue 33, Page A23