The work addresses the thorny problem of waste heat. Thanks to the second law of thermodynamics, a small amount of heat will always be released into the planet's atmosphere no matter what energy source we use — be it nuclear, solar, or wind — because no energy system is 100 percent efficient.

"You can think of it like a leaky bathtub," study coauthor Manasvi Lingam, an astrobiologist at the Florida Institute of Technology, told LiveScience. A small leak in a bathtub that's barely filled doesn't let out a lot of water. But as the tub continues to get filled — and our energy demands grow — that tiny leak can flood the whole house, Lingam explained.

I thought the problem was that CO~2~ was acting like a blanket trapping in all the heat. Is this "heat leaking" really a problem? If so, what about solar cells then?