Climate change is causing ice to melt at an alarming rate, and two studies warn of potentially dire consequences.
In one such case, fresh water extracted from melting ice could upset the delicate balance that fuels the weather for millions of people. In another case, scientists have new concerns about how quickly the ice in Antarctica will melt, which could lead to a significant and rapid rise in sea levels.
In the first study, scientists say the Atlantic Overturning Circulation (AMOC) — the ocean current at the center of the fictional (and scientifically inaccurate) movie “The Day After Tomorrow” about climate change catastrophe — is on track to collapse in the future.
The study, based on computer model simulations, renews concerns about the stability of the critical stream that fuels weather and climate patterns in the United States, Europe and Africa. Previous studies have found that a collapse of the AMOC is possible sometime this century, so this study adds to ongoing research into its current and future behavior.
Meanwhile, a second study published this week warns of how suddenly ice melting in Antarctica could lead to a significant and devastating rise in sea levels around the world.
How can the AMOC break down?
There is simply too much fresh water – coming from the melting Greenland ice sheet, melting sea ice, combined with increased rainfall and river runoff.
The collapse of the AMOC is a well-known element of climate change: “One of the most prominent elements of climate change is the Atlantic Overturning Circulation (AMOC), which can collapse due to freshwater inputs into the North Atlantic Ocean,” said the study, published in the peer-reviewed journal Science Advances. counterparts.
To conduct the simulation, researcher Rene van Westen and colleagues at Utrecht University in the Netherlands simulated the gradual increase in freshwater inputs to the North Atlantic Ocean over 2,200 years, which they say led to a sudden AMOC.
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When is a collapse possible?
However, the study's authors said they could not determine or even estimate when it would collapse: “This setup does not allow us to say anything about the current distance to the AMOC tipping point,” Van Westen told USA TODAY. . “We can only say something about the direction in which the AMOC is headed. The physics-based indicator suggests that we are moving towards a turning point.”
Upcoming simulations and studies will provide more detail on how (and perhaps when) AMOC advises under climate change, he said.
If it collapses, it could lead to an ice age in Europe and sea level rise in cities like Boston and New York, as well as more powerful storms and hurricanes along the East Coast.
What does the Antarctic study say?
In the Antarctic study, published this week in the journal Nature Geoscience, scientists report the first direct evidence that the West Antarctic Ice Sheet suddenly and dramatically shrank at the end of the last ice age, about 8,000 years ago, according to a statement from the University of Antarctica. University of Cambridge in the United Kingdom
The study says this is the first evidence anywhere in Antarctica of such rapid ice loss.
The study provides a blueprint for what could happen today, as global warming causes ice sheets to melt. “Scientists are concerned that today’s rising temperatures could destabilize parts of the West Antarctic Ice Sheet in the future, potentially crossing a tipping point and causing runaway collapse,” according to the University of Cambridge.
Such a collapse would contribute to potentially catastrophic sea level rise around the world. Overall, if the West Antarctic ice sheet melts, it could cause sea levels on the planet to rise by more than 16 feet, which over time would submerge coastal towns and cities around the world.
