Earth enters a 'new reality' as coral decline tipping point reached

A major scientific report released today has delivered a stark warning: the world has crossed a critical planetary threshold, with warm-water coral reefs – vital to marine biodiversity and the livelihoods of nearly a billion people – now tipping into irreversible decline.

The second Global Tipping Points Report, published by the University of Exeter in partnership with 87 institutions across 23 countries, reveals that coral reefs are the first of several Earth system tipping points humanity is beginning to cross, as the planet nears or exceeds 1.5°C of global warming.

“The reality is sinking in – coral reefs as we know them are vanishing,” said Professor Tim Lenton, Director of the Global Systems Institute and lead author of the report. “We’re seeing the start of widespread dieback that, without urgent reversal of global heating, will lead to the near-total collapse of warm-water coral ecosystems.”

These findings land just as ministers and negotiators gather in Brazil ahead of COP30. With the Amazon rainforest – itself approaching a critical tipping point – as the summit’s backdrop, scientists are calling on global leaders to act decisively to prevent further irreversible damage to Earth’s climate systems.

Beyond coral reefs, the report warns of looming risks from the melting of polar ice sheets, the collapse of the Atlantic Meridional Overturning Circulation (AMOC), and the dieback of the Amazon – tipping points that would have catastrophic implications for both people and planet.

The risk of crossing these thresholds grows with every fraction of a degree above 1.5°C. The report urges policymakers to take rapid steps to minimise the “overshoot” – the time spent above this critical temperature – by accelerating emissions reductions and deploying sustainable carbon removal strategies.

“The science is clear. Current policies are not sufficient,” said Dr Manjana Milkoreit of the University of Oslo. “We need governance systems that are agile, forward-looking and capable of managing tipping risks with urgency.”