Global warming was crossing dangerous thresholds sooner than expected with the world’s coral reefs now in an almost irreversible die-off, marking what scientists on Monday described as the first “tipping point” in climate-driven ecosystem collapse.

The warning in the Global Tipping Points report by 160 researchers worldwide, which synthesises groundbreaking science to estimate points of no return, came just weeks ahead of this year’s Cop30 climate summit being held at the edge of the Amazon rainforest in Brazil.

That same rainforest system was at risk of collapsing once the average global temperature warmed beyond just 1.5 degrees Celsius based on deforestation rates, the report said, revising down the estimated threshold for the Amazon.

Also of concern if temperatures kept rising was the threat of disruption to the major ocean current called the Atlantic Meridional Overturning Circulation, or AMOC, which helps to ensure mild winters in northern Europe.

“Change is happening fast now, tragically, in parts of the climate, the biosphere,” said environmental scientist Tim Lenton at the University of Exeter, who is the lead author of the report.

Lenton noted positive signs when it came to phasing out the fossil fuels most responsible for climate change. Renewables, for example, accounted for more electricity generation than coal this year for the first time, according to data from the non-profit think tank Ember.