Story at a glance
- Global warming is increasing average temperatures across Earth and causing extreme weather events.
- At the same time, a new study found that temperatures in the upper atmosphere of the Earth are cooling.
- These changes could have an effect on both weather and airplane technology.
If global warming is occurring, how can the Earth’s atmosphere be getting colder?
In some ways, this question echoes another by climate change skeptics: If global warming is occurring, why is it colder in some places than previous years? For one thing, weather and seasons are still happening. At the same time, colder weather in some areas is countered with hotter temperatures in other places, and research suggests that global warming might actually be releasing trapped cold air.
In the same way, even as the lower atmosphere is warming, a new study found that the Earth's upper atmosphere is actually cooling due to rising carbon dioxide levels and changes in the magnetic field.
“The increase in CO2 concentration is the main cause of cooling in the upper atmosphere, while effects of magnetic field changes also play a role near the poles, especially in the Northern Hemisphere," concluded Ingrid Cnossen, a fellow at the British Antarctic Survey and author of the study.
While the troposphere, the layer closest to the Earth, cools as you go higher, the next level — the stratosphere — actually warms as you get closer to the sun. Even higher layers, including the mesosphere and thermosphere, are generally cold, but the study found that temperatures have been dropping even further in all three layers.
It’s not clear whether global warming, which affects the troposphere, is behind the cooling of upper layers, Cnossen said, but these effects of climate change could have serious consequences on everything from melting glaciers to humans’ ability to fly.
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