Global Warming Is Changing the World

An international climate assessment finds for the first time that humans are altering their world and the life in it by altering climate; looking ahead, global warming's impacts will only worsenIn early February, the United Nations--sponsored Intergovernmental Panel on Climate Change (IPCC) declared in no uncertain terms that the world is warming and that humans are mostly to blame. Last week, another IPCC working group reported for the first time that humans--through the greenhouse gases we spew into the atmosphere and the resulting climate change--are behind many of the physical and biological changes that media accounts have already associated with global warming. Receding glaciers, early-blooming trees, bleached corals, acidifying oceans, killer heat waves, and butterflies retreating up mountainsides are likely all ultimately responses to the atmosphere's growing burden of greenhouse gases. "Climate change is being felt where people live and by many species," says geoscientist Michael Oppenheimer of Princeton University, a lead author of the report. "Some changes are making life harder to cope with for people and other species."