+**Permafrost** is ground, including soil and rock, that remains completely frozen for at least two consecutive years, often spanning millennia. This ancient, icy foundation underlies a quarter of the Northern Hemisphere, trapping vast stores of organic material and gases. Its thawing due to [Climate Change](/wiki/Climate_Change) is reshaping [Arctic](/wiki/Arctic) landscapes and releasing potent greenhouse gases into the atmosphere.
+## See also
+- [Cryosphere](/wiki/Cryosphere)
+- [Tundra](/wiki/Tundra)
+- [Carbon Cycle](/wiki/Carbon_Cycle)
... 1 more lines