地球的“冰盖子”漏了：谁打开了北极的地下潘多拉魔盒？
Permafrost — ground that has remained frozen for at least two years in a row — covers vast areas of the Arctic. For thousands of years, this frozen layer has acted as a giant cap, locking away huge amounts of carbon and preventing it from entering the atmosphere. However, new research warns that this natural barrier is breaking down much faster than expected.
A recent study published in the journal Earth’s Future reveals that when permafrost thaws, it becomes 25 to 100 times more permeable. In simple terms, as the ice melts, the soil turns into a sponge with wide-open holes, allowing climate-warming gases like carbon dioxide and methane(甲烷) to escape freely.
Scientists estimate that permafrost currently holds about 1,700 billion tons of carbon. That is roughly three times the amount of carbon already floating in our atmosphere today. The study, led by researchers at the University of Leeds, involved laboratory experiments that gradually warmed frozen soil samples from -18°C to +5°C. They found the most dramatic change in gas release happened when temperatures rose just above freezing — between -5°C and 1°C.
This process creates a dangerous feedback loop. As global temperatures rise, more permafrost melts. As it melts, more greenhouse gases are released, which in turn causes the planet to warm even further. “The release of huge amounts of carbon that have been stored in frozen soils is a very real danger,” said Professor Paul Glover, who led the research. “The Arctic is already warming four times faster than the rest of the world, and this could make that situation worse.”
While the findings are mainly focused on carbon and methane, researchers note there may be other hidden risks. Thawing ground could also release radon(氡), a radioactive gas linked to cancer, which might pose health threats to communities in northern regions.
The researchers stress that while these are early results, they provide clear evidence that the Arctic’s melting ice is not just a sign of climate change — it is a driver of it.
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