Earth’s upper atmosphere is cooling more than 10 times faster than natural rates. A new study reveals why: while CO₂ traps heat near Earth’s surface, it also makes the stratosphere radiate infrared energy into space more efficiently, creating a key fingerprint of human-caused climate change.

Earth’s upper atmosphere is cooling more than 10 times faster than natural rates. A new study reveals why: while CO₂ traps heat near Earth’s surface, it also makes the stratosphere radiate infrared energy into space more efficiently, creating a key fingerprint of human-caused climate change.