Permafrost (noun, “PUR-mah-frost”)
This is any soil that has been frozen for at least two years straight. In polar regions, air temperatures are below freezing for many months of the year, which allows the soil below to freeze. During summer, upper soil layers may thaw, allowing plants to grow. But underneath, a deep layer of soil remains permanently frozen.
In a sentence
Permafrost stores elements such as carbon — but if that soil thaws, it could release this contributor to climate change.
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