May 2016 was the 13th consecutive month of record global temperatures
Higher levels of carbon dioxide in the atmosphere lead to a more acidic ocean.
June 1 marks the first day of the Atlantic hurricane season.
Each of the National Parks faces unique challenges from climate change, including increased heat.
April 2016 was the hottest April on record globally.
Temperatures we think of as normal are getting warmer.
The monthly variability in the number of tornadoes has been increasing over the past 50 years.
While there are fewer days each year with tornadoes, on average, the number of days with more than 30 tornadoes is increasing.