The warming of our planet is overwhelmingly due to the extra carbon dioxide in the atmosphere, which accounts for an extra 380 terawatts of heat energy. By comparison, the extra warming that’s a direct consequence of all the fossil fuels we burn and nuclear power we  produce is tiny — just 16 TW.

But that doesn’t mean that the campfire-like warming effects of all that energy we’re unleashing are trivial. For example, Mark Flanner of the National Center for Atmospheric Research has calculated that waste heat could directly warm industrialized parts of the world by between 0.4 °C and 0.9 °C by 2100, reports New Scientist.

The quirky thing about waste heat is that even though it’s small now, if we were to go completely nuclear and at the same time continue the rapacious rate at which we use more power — which goes up about two percent per year — in a century or three the amount of waste heat we’re producing could have significant warming effects all on its own.

What’s the solution? Solar all the way.

Grist thanks its sponsors. Become one.

If you turn the sun’s energy into electricity and use it to boil your kettle, it won’t make the planet any warmer than if that same energy had instead gone into heating up the tiles on your roof. But if you boil your kettle using energy from fossil fuels or a nuclear power plant, you are adding extra heat.