A heat wave struck the Midwest in late August and early September 2013. This map shows the hottest temperatures in the United States between August 1 and September 8, 2013, based on data from NOAA's Real-Time Mesoscale Analysis.

In late July and early August, unusually high temperatures dominated Europe, from the Mediterranean Sea northward to Scandinavia and the British Isles.This map shows temperature between July 16 and August 11, 2013, compared to the 1981-2010 average for the same time of year.

The extent of snow-covered ground in the Northern Hemisphere at the end of the cold season (June) hit a record low. Annual average snow cover extent has not exceeded the long-term average even once since 2003. Between 1979 and 2011, the snow cover in June is declining even faster than the end-of-summer Arctic sea ice extent.

Glacier mass balance in 2011 (the most recent year for which worldwide analysis is complete) was negative, and preliminary data indicate that 2012 will probably be the 22nd consecutive year of net losses in glacier mass. Between 1980 and 2011, glaciers around the world lost the water equivalent of 15.7 meters. That would be like slicing a roughly 17-meter-thick slab off the top of the average glacier and repeating that exercise worldwide.

The summer of 2012 brought Greenland far more extensive melt than anything observed in the satellite record: in July 2012, surface melt extended over nearly the entire ice sheet. The standardized melt index was nearly double the previous record.

Boy eating a peanut butter sandwich

The average U.S. citizen consumes around 3.5 pounds of peanut butter a year. Will global warming make climate conditions less peanut-friendly in the U.S.?

Arctic sea ice extent set a new record low at the end of the summer melt season on September 16, 2012. But extent is not the only quality of the ice that is changing. Wind and ocean circulation patterns are conspiring with a warmer climate to reduce the amount of year-round (multi-year) ice, transforming the remaining ice into a younger, thinner version of its old self.

Since the mid-1950s, easy-to-serve, portion-controlled fish sticks have regularly found their way onto U.S. dinner tables and into school lunches. The past decade, however, has given fishermen and scientists a preview of the challenges they may face in keeping fish sticks on the menu as the planet gets warmer.