Researchers: Earth’s “freezer” is thawing – too late to stop
Earth’s frozen regions have been so significantly affected by global warming that the fundamental conditions for human societies are now under threat. And reversing this trend is difficult.
“We are very late to act; limiting the damage is now crucial,” says researcher Lan Wang-Erlandsson.
Scientists have long known that the cryosphere—Earth’s frozen regions—is vital to the planet’s climate system, yet it has proven difficult to monitor.
A new study, led by Swedish researchers, draws on the latest research in the field and concludes that the cryosphere has moved beyond what is known as its “planetary safe operating space.”
“We have stepped outside the environmental boundaries that are absolutely fundamental to human societies—the very conditions that once enabled civilization to take root,” says Lan Wang-Erlandsson, a co-author and researcher at the Stockholm Resilience Centre.
Warming faster than the global average
The cryosphere is currently warming much faster than the planet as a whole. In recent years, the acceleration of melting—and the consequences that follow—has become increasingly apparent. Lan Wang-Erlandsson points to the permafrost near the North Pole as an example.
“You could call it Earth’s freezer; it stores thousands of years of accumulated organic carbon.” As it thaws, carbon dioxide is released; if this occurs underwater, it leads to oxygen depletion. In oxygen-depleted conditions, methane is produced, which in turn accelerates global warming.
Regarding certain parts of the cryosphere, researchers fear that we may have already passed so-called "tipping points"—thresholds beyond which the process can no longer be reversed.
An uncompromising negotiator
The loss of these frozen regions is driven primarily by human-induced climate change. According to researchers, drastic reductions in emissions are now urgently required. Lan Wang-Erlandsson likens the cryosphere to an uncompromising negotiator.
"It mirrors our emissions. If you view it as a party to the negotiations, it essentially says: 'If you emit more, we will also emit more. But if you emit less, we will do the same.'"
She adds that the cryosphere also holds a number of "wild cards"—unpredictable factors whose exact nature and timing remain unknown, though it is certain that they are influenced by our emissions.
A further complication is the inherent inertia in the system, meaning that future changes are already "locked in" and beyond our control. This further narrows the scope for action.
"A vast amount of the ice and permafrost that has been lost cannot be recovered in the foreseeable future—which makes the need for action all the more urgent."
Facts
The Cryosphere
The cryosphere comprises the parts of the Earth covered by ice and snow, whether seasonally or year-round. Together, these areas cover more than 15 percent of the Earth's surface. Some of the most important components of the cryosphere are the Antarctic ice sheet, the Greenland ice sheet, Arctic sea ice, glaciers and snow, permafrost, and the polar oceans—that is, the Arctic and Southern Oceans.
Changes in these areas serve as clear indicators of climate change. Ice loss in these regions poses increased risks to ecosystems and human societies across the globe.
As early as the 1990s, it became evident that rising temperatures resulting from carbon dioxide emissions are causing parts of the cryosphere to shrink dramatically.
Almost all changes resulting from the loss of the cryosphere are essentially permanent, persisting for hundreds or thousands of years.
Source: The International Cryosphere Initiative.
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