Here are 3 dangerous climate tipping points the world is on track for – NPR

by | Nov 10, 2022 | Climate Change

An iceberg in Ilulissat, Greenland. Ice sheets in Greenland and Antarctica are melting rapidly, and that melt will accelerate as the Earth heats up.

Ryan Kellman/NPR

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Ryan Kellman/NPR

The goal of the international climate meeting underway in Egypt is to limit global warming to 1.5 degrees Celsius, compared to temperatures in the late 1800s. Even at that level, communities will experience more dangerous storms, flooding and heat waves. But if the planet heats up beyond 1.5 degrees, the impacts don’t get just slightly worse. Scientists warn that abrupt changes could be set off, with devastating impacts around the world.

Notes
Global temperatures have increased nearly 2 degrees Fahrenheit since the late 1800s. Here, federal scientists show that change using the average temperature over each 5-year period going back to 1880.

Credit: NASA

Such changes are sometimes called climate tipping points, although they’re not as abrupt as that term would suggest. Most will unfold over the course of decades. Some could take centuries. Some may be partially reversible or avoidable. But they all have enormous and lasting implications for the humans, plants and animals on Earth. And they are looming. It’s still possible to avoid such widespread calamities, but only if countries move far more aggressively to cut the pollution driving climate change. The Earth has warmed about 1 degree Celsius so far. If countries, including the United States, follow through on current promises to reduce greenhouse gas emissions, the latest estimates suggest that Earth’s temperature will still top out around 2.8 degrees Celsius of warming.

Here are the three most important and well-studied changes, from collapsing ice sheets to thawing Arctic permafrost, to disappearing coral reefs.

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A group of scientists from the United Kingdom trek up to a research site on the west side of the Greenland ice sheet near Kangerlussuaq in the summer of 2022. This year marks the 26th year that Greenland has lost more ice than it gained.

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Change #1: Ice sheets in Greenland and West Antarctica could collapse Ice sheets are the massive expanses of ice that cover Greenland and Antarctica, and which contain about two thirds of the freshwater on Earth. Climate change is already causing them to melt, and raising sea levels around the world. But if the Earth lingers at, or above, 2 degrees Celsius of warming, as it is on track to, that melting will steadily accelerate. Scientists warn that will cause parts of the ice sheets to collapse, sending massive amounts of water into the world’s oceans. The million dollar question is how quickly that collapse will occur. “Collapse tends to be a bit of a loaded world. People think of it like a building collapse,” says Ian Joughin, a glaciologist at the University of Washington who has spent decades studying how giant glaciers move and change. “Maybe a better timescale for an ice sheet [collapsing] is the Roman Empire,” Joughin explains. Like a dying empire, the ice sheets in Greenland and West Antarctica are huge. It will take decades or even centuries for them to disintegrate.

Snow and ice are melting more quickly than they are being replaced on the world’s largest ice sheets. That’s causing the ice sheets to get out of balance and rapidly destabilize, sending enormous amounts of freshwater into the ocean and driving global sea level rise.

Ryan Kellman/NPR

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This year marks the 26th year that Greenland has lost more ice than it gained. Last year, rainfall was recorded at the ice sheet’s highest point, rather tha …

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