- Are we already seeing the effects of climate change? The new draft says yes. Scientists are surer that the Earth has experienced more heat waves caused by global warming.
- Since the international panel published its last report in 2007, scientists around the world have published more studies and stronger science on future sea level rise. Thus, the panel adjusted its expectation for the upper limit for how high that rise will likely be. It now expects rises between about 1 to 3 feet (29 to 82 centimeters) by the end of the century. Its 2007 estimate was about 7 inches to 2 feet.
- Even as scientists become more sure that the world is warming overall, they're still having a hard time predicting exactly what will happen to individual places. That makes it difficult for lawmakers to ready their towns and countries.
- Scientists may be less sure about how much climate change has contributed to other events. Compared to the panel's 2007 report, the latest report finds it's less certain that people are already experiencing climate change-driven tropical cyclones and droughts.
- Some details in the report may still change this fall. The draft is scheduled for further discussion and revisions, Intergovernmental Panel on Climate Change spokesperson Jonathan Lynn told the BBC. In the past, however, such late drafts have not changed much after final discussion, The New York Times reports.