He wasn't always so strong on the threat of climate change.
But there may be some other downsides.
Both NASA and NOAA agree: The planet just set an ominous new record.
The last thing America actually needs is another Keystone debate. But there are really helpful things Congress could be doing instead to protect the environment and boost the economy.
The U.S. government advises Americans not to idle their cars in winter. Many are doing it anyway.
Putting to rest the myth that global warming is "slowing down."
We may find a bottom in the first half of 2015.
How Pope Francis proves that science and religion don't have to be in conflict.
Sleeping, exercise, friends and hobbies are not just a good life choice, but a good energy choice.
The radiation is well below levels deemed dangerous.
Auto experts say you don’t need to idle your car to warm it up. Yet people keep doing it.
These new technologies, in combination, could shrink suburbanites' energy footprints down to city-size.
Vladimir Putin is trotting out conspiracy theories about oil prices. He’s not the first
AAA says prices have now plunged for longer than they did during the Great Recession.
New York banned fracking not because of science – but because of its absence.
A happier, healthier life may also be better for the environment
New NASA images show how all around the world, cities increase their nighttime light usage during the holidays.
New studies outline alarming new findings about the stability of the Greenland ice sheet.
One Rufa red knot is known to have flown 400,000 miles in his life -- a distance equivalent to a trip to the moon and halfway back. Will there ever be another like him?
Oil is going down, down, down.