The planet has entered a “new reality” due to climate change, as tropical coral reefs are believed to have crossed an irreversible tipping point, according to a major new scientific report released Sunday.
The study, authored by a team of 160 international scientists, warns that the Earth’s systems are approaching multiple thresholds that could trigger irreversible transformations in ecosystems — creating a domino effect with global consequences. “We are now almost certain that we have passed one of the tipping points for warm-water tropical coral reefs,” said Tim Lenton, an environmental researcher at the University of Exeter, in comments to AFP.
Coral bleaching reaches unprecedented levels
With global temperatures already 1.4°C higher than in the pre-industrial era, coral reefs are suffering unprecedented degradation, the report finds. This loss threatens the livelihoods of millions of people and the survival of up to one million marine species that depend on reef ecosystems.
Since their last study in 2023, researchers have observed record coral mortality rates. Reefs are undergoing mass bleaching events that have persisted for two consecutive years — a clear sign of ecological collapse.
Coral reefs in the “danger zone”
Coral reefs act as natural barriers against coastal erosion, store carbon dioxide, and support rich biodiversity. Rising ocean temperatures cause corals to expel the symbiotic organisms that provide them with color and nutrients, leaving them to starve and eventually die.
Dead corals quickly become skeletal structures overrun by algae, losing their ecological function.
If temperatures rise to 1.5°C above pre-industrial levels, scientists warn that most coral reefs will be doomed — a threshold expected to be breached within years unless greenhouse gas emissions are drastically reduced.
This target — the most ambitious goal of the Paris Agreement (2015) — is now “on the brink of collapse,” UN Secretary-General António Guterres recently cautioned. “Exceeding it would push the world into a danger zone — an even greater one,” said Lenton.
Urgent call ahead of COP30
The release of the study coincides with global climate negotiations in Brasília, where delegates are preparing for COP30, to be held next month in Belém, Brazil.
Researchers warn that more tipping points are approaching, including the melting of polar ice, collapse of vital ocean currents, and destruction of the Amazon rainforest, which will host the climate summit. “We are rapidly approaching multiple planetary tipping points that could transform our world, with catastrophic consequences for people and nature,” Lenton warned.
“This demands immediate and unprecedented action from leaders at COP30 and policymakers worldwide.”
Glimmers of hope: renewable energy gains ground
Despite the grim findings, scientists note some positive developments in the past two years — what they call “positive tipping points.”
Solar and wind energy are now cheaper than ever, and the adoption of electric vehicles, battery storage, and heat pumps is accelerating in key markets. Meanwhile, emerging clean technologies such as green hydrogen and ammonia could soon reach large-scale viability.
Still, researchers stress that progress in renewables will not compensate for the irreversible loss of coral ecosystems, which once acted as one of the planet’s most vital life-support systems.
