The group of researchers, who published a commentary in the journal Nature
, say there is growing evidence to suggest that irreversible changes to the Earth’s environmental systems are already taking place, and that we are now in a “state of planetary emergency.”
A global tipping point is a threshold when the planet’s systems go beyond the point of no return — such as the loss of the Amazon rainforest, accelerated melting
of ice sheets, and thawing of permafrost
— the authors of the commentary say.
Such a collapse could lead to “hothouse” conditions
that would make some areas on Earth uninhabitable.
“We argue that the intervention time left to prevent tipping could already have shrunk towards zero, whereas the reaction time to achieve net zero emissions is 30 years at best,” the authors said.
Active problem areas
Led by Timothy Lenton, professor of climate change and Earth system science at the University of Exeter, in southwest England, the team identified nine areas where they say tipping points are already underway.