Scientists say that warming has breached a critical threshold for tropical coral reefs, which are expected to see catastrophic losses in the years ahead. They warn that if warming continues unchecked, the world will cross other climate “tipping points,” destabilizing ice sheets, disrupting ocean currents, and causing irreversible damage to the Amazon rainforest.
The Earth has warmed by at least 1.3 degrees C since the preindustrial era, surpassing the point at which warming is expected to inflict widespread damage on reefs in warm, shallow, sunlit waters. The loss of reefs would have ramifications for the hundreds of millions of people worldwide who depend on them for food or income, according to a landmark new report authored by 160 scientists in 23 countries. The report says that countries must work to preserve any surviving reefs by protecting them from pollution and overfishing.
The world already risks the collapse of the massive West Antarctic Ice Sheet, according to the report. And if warming breaches 1.5 degrees C, the stated goal of the Paris Agreement, humanity may also face a mass dieback of the Amazon rainforest and the collapse of a vital Atlantic current.
“Current policy thinking doesn’t usually take tipping points into account,” said coauthor Manjana Milkoreit, of the University of Oslo. She warned that to avoid reaching key tipping points, the world must make deep cuts to emissions now, rather than later, and that countries must be prepared to draw down atmospheric carbon if warming surpasses 1.5 degrees C, which scientists say is a near certainty.
The new report comes ahead of the next round of U.N. climate talks, to be held in Brazil next month. “As we head into the COP30 climate negotiations it’s vital that all parties grasp the gravity of the situation,” said coauthor Mike Barrett, chief scientific adviser at the World Wide Fund for Nature in the U.K. “Countries must show the political bravery and leadership to work together and achieve them.”
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