A University of Exeter study warns Earth may be approaching multiple ecological tipping points as global temperatures are projected to surpass a 1.5°C rise above pre-industrial levels within five years. Coral reefs are particularly vulnerable: roughly 80% are affected by a record mass bleaching event, and severe heat can kill up to 90% of corals. Researchers have identified more than two dozen potential tipping points — from polar ice melt to ocean circulation changes and rainforest die-off — though efforts to breed heat-tolerant corals and accelerate climate action offer limited hope.
New Study Warns Earth Is Near Multiple Ecological Tipping Points — Coral Reefs Could Be First to Collapse
A University of Exeter study warns Earth may be approaching multiple ecological tipping points as global temperatures are projected to surpass a 1.5°C rise above pre-industrial levels within five years. Coral reefs are particularly vulnerable: roughly 80% are affected by a record mass bleaching event, and severe heat can kill up to 90% of corals. Researchers have identified more than two dozen potential tipping points — from polar ice melt to ocean circulation changes and rainforest die-off — though efforts to breed heat-tolerant corals and accelerate climate action offer limited hope.
11:12 AM, 11/10/2025Environment
New research raises alarms about ecological tipping points
Seen from space the planet may look unchanged, but a newly published study from the University of Exeter warns Earth could be approaching several ecological tipping points. Scientists now predict global temperatures may exceed a 1.5°C rise above pre-industrial levels within the next five years, placing major ecosystems and climate drivers at heightened risk of irreversible change.
Coral reefs are among the most immediate victims. Stanford marine scientist Stephen Palumbi, Ph.D., who studies reefs worldwide, notes decades of observation show widespread degradation. An estimated 80% of reefs are now affected by the largest mass bleaching event on record. Bleaching occurs when heat stress forces the symbiotic algae that feed corals to leave or die, leaving corals weakened and often starving.
“Almost every reef I've been to has become progressively more damaged over time,” says Stephen Palumbi, Ph.D., a professor of marine sciences at Stanford's Hopkins Marine Station.
Depending on the intensity of a heating event, bleaching can cause very high mortality: in severe episodes, up to 90% of corals can die. While some species can recover, many cannot, risking large-scale reef loss with cascading impacts on fisheries, coastal protection and biodiversity.
Researchers have identified more than two dozen potential tipping points, ranging from the melting of polar ice sheets (which accelerates sea level rise) to disruptions of major ocean circulation patterns and die-off of tropical rainforests such as the Amazon, each of which would alter weather, carbon cycles and human livelihoods.
“These tipping points are now within a range of warming that is, unfortunately, reachable,” says Peter Roopnarine, Ph.D., an evolutionary ecologist at the California Academy of Sciences. “They may not all trigger simultaneously, but many are now within reach of continued global warming.”
Despite the urgency, researchers point to emerging interventions that offer limited hope. Teams are developing methods to rescue and breed heat-tolerant corals, collecting diverse, resilient strains and breeding them to produce offspring better able to withstand warming oceans. Meanwhile, momentum for emissions reductions and other climate solutions could help reduce the likelihood of crossing the most dangerous thresholds.
Nevertheless, scientists stress the window to act is closing. The study's warnings arrive as the COP30 climate conference is scheduled to begin next week in Brazil — a critical moment for international commitments to reduce emissions and fund adaptation and restoration efforts.
What this means for readers
Loss of coral reefs and the triggering of other tipping points would have widespread ecological, economic and social consequences. Policy action, rapid emissions cuts, and targeted ecological interventions are all needed to reduce risk and buy time for nature and communities to adapt.