What countries will heat up the most in a 2°-warmer world: the need for air conditioning will skyrocket, with Africa and Europe hit hardest.

One of the more threatening aspects of climate change is its potential to unleash feedbacks, or situations where warming induces changes that drive even more warming. Most of those are natural, such as a warmer ocean being able to hold less carbon dioxide, resulting in even more of the greenhouse gas in the atmosphere.

But at least one potential feedback has a very human element: air conditioning.

A lot of the carbon dioxide we emit comes from the production of electricity. The heat those emissions generate causes people to run air conditioning more often, which drives more electricity use, which drives further emissions. It's a feedback that will remain a threat until we manage to green the electrical grid.