See the trend in hot days in these U.S. cities.
A small increase in average temperature leads to a big increase in extreme heat.
Here's how the decline in coal use is linked to climate-friendly cars.
The first day with summer-like temperatures is happening earlier for most of these cities.
Since the first Earth Day in 1970, the average annual temperature in every state has climbed.
More water is flowing this year in California from frequent storms and melting snowpack.
Western snowpack at the end of the the wet season is up this year — but that's less likely in the future.
As the climate changes, see the trend in warmer-than-normal spring days in these cities.