SOURCE: Mother Jones

DATE: September 25, 2019

SNIP: Climate change has already taken an irreversible toll on our oceans and frozen places, warns a major new report from the United Nations’ Intergovernmental Panel on Climate Change.

Much of the carbon pollution we’ve pumped into the air has gone directly into the world’s seas: They have absorbed 90 percent of the excess heat from the atmosphere, warming without pause for the past 50 years. Because oceans are so unfathomably big and complex—covering two-thirds of Earth’s surface—that warming has consequences for the entire planet.

The IPCC Special Report on Ocean and Cryosphere In A Changing Climate is a collaboration among 130 scientists around the world who have assembled data from more than 7,000 papers. The new report manages to paint an even bleaker picture, showing that the oceans have been expanding, acidifying, and losing oxygen at an accelerated rate.

One major takeaway from the report: The seas are rising twice as fast as twentieth century averages. The ocean is also heating up twice as fast, absorbing more carbon and acidifying. “The rate of climate change has actually gone up,” lead author of the report’s chapter on oceans, Nate Bindoff of the University of Tasmania, said in a call with reporters. This acceleration of warming and acidification means a cascade of impacts on weather and marine life, such as coral reefs, some of which we still don’t fully understand.

The IPCC looks at a range of possible climate-change scenarios, from unabated pollution to dramatic reforms in the next decade. Right now, though, the world is on the most dangerous warming path.

Our climate has already warmed around 1 degree Celsius above preindustrial times, and time is running out until we overshoot global goals to contain warming to below a catastrophic 2 degrees. “Even if we turned off greenhouse gas emissions tomorrow we’d have another 0.3 to 0.4 degrees [Celsius] of additional warming,” added Bindoff. Just that amount of warming will reshape the lives of more than a billion people who rely on ice or fishing for their livelihoods in low-lying coastal regions, high-mountain areas, and the Arctic. If we don’t limit our carbon emissions, those effects will spread far beyond the most vulnerable coastal areas in the latter part of the century.

Indigenous communities in the Arctic are already among the people “reaching adaptation limits,” says the report: Their civilizations are threatened by the melting of the Arctic sea ice and permafrost, or frozen soil.