New Study Has Grim News on Climate 'Tipping Points'

For many years, scientists have warned that our failure to cut emissions and limit global warming is moving the world closer to "tipping points" where changes become irreversible and self-perpetuating. In a major new study published in the journal Science, researchers say they have identified the timescale and temperature rises for those tipping points in greater detail than ever before—and with five of them, current warming levels have already placed us at the lower end of the threshold, bringing the world to the brink of disastrous changes, the Guardian reports.

Triggering of the tipping points will lead to "substantial sea level rise from collapsing ice sheets, dieback of biodiverse biomes such as the Amazon rainforest or warm-water corals, and carbon release from thawing permafrost," the researchers wrote. The five tipping points we are on the brink of include the collapse of the Greenland and Western Antarctica ice sheets, the die-off of tropical coral reefs, the abrupt thaw of carbon-rich permafrost, and the collapse of the Labrador Sea current, which would bring extreme weather to Europe. Other tipping points listed include the dieback of the Amazon rainforest and northern forests, along with the collapse of more ice sheets and ocean currents.

Researcher Johan Rockström, director of the Potsdam Institute for Climate Impact Research, says the team reached the "very dire" conclusion that multiple tipping points will be reached at warming of 1.5 degrees Celsius above preindustrial levels, not far from the current warming level of 1.1 degrees Celsius, or 2 degrees Fahrenheit, the New York Times reports. He says that makes it all the more important to reach the emissions cuts goals set out in the Paris Agreement and limit warming to 1.5 degrees Celsius—but even if those goals aren't met, the world shouldn't give up. In the fight to avoid tipping points, "every 10th of a degree counts," he says. "So 1.6 is better than 1.7 and so on." The AP notes that current policies put the planet on course for a rise of 2.7 degrees Celsius. (More climate change stories.)