On April 6, the United Nations released a report that warns of changes in the world's weather and ecosystems as a result of global warming. The Intergovernmental Panel on Climate Change (IPCC) said more heat waves, droughts and floods are likely if people don't take steps to stop climate change.
More than 200 scientists worked on the report, the second of four. The IPCC study explains the effects that a warmer world would have on species, water supplies and ice sheets. The next report will address strategies to deal with global warming. "It is vital that international action is taken now to avoid dangerous climate change," says Achim Steiner of the U.N. Environment Program.