Scientists say the world’s coral reefs are almost irreversibly dead

Global warming has crossed dangerous thresholds sooner than expected, with the world’s coral reefs now in a state of almost irreversible extinction, marking what scientists described Monday as the first “tipping point” in climate-induced ecosystem collapse.

Warning in Global turning points report By 160 researchers around the world, which brings together leading science to estimate tipping points, it comes just weeks before this year’s COP30 climate summit, which will be held on the edge of the Amazon rainforest in Brazil.

The rainforest system itself is now at risk of collapsing once the average global temperature rises above 1.5 degrees Celsius based on rates of deforestation, which adjusts the estimated threshold for the Amazon, the report said.

Also of concern, if temperatures continue to rise, is the threat of disruption of a major ocean current called the Atlantic Overturning Circulation, or AMOC, which helps ensure mild winters in northern Europe.

“Change is now happening rapidly, and dramatically, in parts of the climate and biosphere,” said ecologist Tim Linton of the University of Exeter, lead author of the report.

Some positive indicators

Linton pointed to positive signs when it comes to phasing out the fossil fuels most responsible for climate change. For example, renewables contributed more to electricity generation than coal this year for the first time, according to data from the nonprofit Ember Research.

Watch | Coral reefs are experiencing a mass bleaching event:

Coral reefs are suffering from mass bleaching

Oceans around the world are experiencing a massive coral bleaching event, according to the US National Oceanic and Atmospheric Administration. This means that corals in all major ocean basins are turning white, or even dying, because the waters in which they live are too hot.

“No one wants to be shocked and weakened,” Linton said. “We still have some agency.”

Scientists called on countries at the United Nations Climate Change Conference (COP30) in November to work to reduce carbon emissions that cause global warming.

Scientists have been surprised by how quickly nature is changing, with average global temperatures already rising 1.3 to 1.4 degrees Celsius above the pre-industrial average, according to data from the UN and European Union science agencies.

Warmest years on record

The past two years have been the warmest on record on Earth, with marine heatwaves pressuring 84 percent of the world’s coral reefs to the point of bleaching and, in some cases, death. Coral reefs support about a quarter of marine life.

Scientists have suggested that for coral reefs to recover, the world will need to dramatically step up climate action to reverse temperatures that are falling to just one degree Celsius above the pre-industrial average.

“The new report makes clear that every year there is an increase in the scale and scale of the negative impacts of climate change,” said Pip Canadel, a senior scientist at Australia’s CSIRO Climate Science Centre.