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Extreme Weather: ‘What’s Causing Unusually Hot Temperatures in the U.S.?’

From PBS via YouTube:

Lack of water, “the great air conditioner”, is causing unusually high temperatures and extreme weather events in the United States, Kevin Trenberth with the National Center for Atmospheric Research tells Judy Woodruff.

Related:

• ‘This summer is ‘what global warming looks like” (Seattle Post-Intelligencer)

(Map credit: NOAA via Climate Central)