Cooling Upper Atmosphere Raises Climate Concerns and Identifies Fingerprint.

Rising CO2 levels are causing the upper atmosphere to cool dramatically, which could have negative effects on orbiting satellites, the ozone layer, and Earth's weather. The cooling aloft is increasing the strength of the human fingerprint of climate change, but also causing concern for atmospheric physicists. The contraction of the upper atmosphere due to cooling is reducing drag on satellites, but also increasing the risk of collisions with space junk. The cooling is also worsening ozone loss in the Arctic, potentially affecting densely populated regions.