Hurricane Katrina battered Bay St. Louis, Miss. Now, developers plan a condo city nearby.
The highest US total is from 1999, which had 676 tornadoes from January to mid-May.
The German research effort is one of the first to attempt 10-year climate forecasts.
Methane levels in the atmosphere rose in 2007 after 10 years. Scientists are trying to find out why.
Politicians at home and abroad question the president's strategy, while new climate studies pour in.