Humanity has entered a “new reality” as the planet crosses its first major climate tipping point,  the large-scale collapse of coral reef ecosystems, a landmark report authored by more than 160 scientists worldwide revealed.

The assessment warns that accelerating fossil fuel use and rising global temperatures are not only intensifying heatwaves, floods, and wildfires, but are now pushing Earth’s natural systems, from tropical rainforests to polar ice caps, toward irreversible breakdown.

“We are rapidly approaching multiple Earth system tipping points that could transform our world, with devastating consequences for people and nature,” said Tim Lenton, a professor at the University of Exeter’s Global Systems Institute and one of the report’s lead authors, published Sunday.

Coral reefs signal first major collapse

The report identifies warm-water coral reefs as the first ecosystem to pass a critical threshold. Since 2023, oceans have been experiencing their most severe and widespread bleaching event in recorded history, affecting over 80% of the world’s reefs as marine heat levels hit new highs.

What was once a vibrant underwater landscape teeming with life has been transformed into vast, bleached expanses overrun by seaweed.

“We have now pushed [coral reefs] beyond what they can cope with,” said Mike Barrett, chief scientific advisor at WWF UK and co-author of the report. Unless global warming is reversed, the authors warned, “extensive reefs as we know them will be lost.”

The consequences extend far beyond marine biodiversity. Coral reefs provide essential habitat for countless species, sustain food security for hundreds of millions, support trillions in global economic value, and shield coastal communities from storm damage.

Wider climate systems near breaking point

Scientists caution that coral reef collapse is only the beginning. The world is on course to surpass the internationally agreed target of limiting warming to 1.5°C above pre-industrial levels, a threshold long viewed as crucial for avoiding runaway climate effects.

Among the most alarming potential scenarios outlined in the report is the breakdown of the Atlantic Meridional Overturning Circulation (AMOC), the vast system of ocean currents that regulates global climate patterns. A collapse of this network, researchers warn, could send some regions into deep freeze while others overheat, disrupt monsoon systems, and accelerate sea-level rise.

“There is now a risk that collapse could occur within the lifetime of people born and living on the planet today,” Barrett said.

World ‘unprepared’ for abrupt, irreversible change

The report stresses that global institutions remain ill-equipped to manage the rapid and interconnected shifts now unfolding.

“Current policies and international agreements are designed for gradual changes, not for these kinds of abrupt, irreversible, and interconnected shifts,” said Manjana Milkoreit of the University of Oslo’s Department of Sociology and Human Geography, who contributed to the study.

How governments respond in the coming years, she added, “could shape the Earth system for a very long time.”

To mitigate the crisis, scientists call for the rapid elimination of planet-heating emissions and expanded efforts to remove carbon from the atmosphere. Lenton said that while surpassing the 1.5°C threshold is now inevitable, the priority must be to limit additional warming and bring global temperatures back down as quickly as possible.

Glimmers of hope amid the alarming findings

Despite its grave conclusions, the report highlights several encouraging developments, noting a “radical global acceleration” in the adoption of renewable technologies, such as solar power, electric vehicles, batteries, and heat pumps. Once established, it adds, cleaner technologies tend to permanently replace polluting ones, as they are both cheaper and more efficient.

The findings arrive just weeks before world leaders convene in Brazil for COP30, the United Nations’ annual climate summit, where nations are expected to announce new emission reduction targets for the next decade.

“This grim situation must be a wake-up call that unless we act decisively now, we will also lose the Amazon rainforest, the ice sheets, and vital ocean currents,” Barrett said. “In that scenario, we would be looking at a truly catastrophic outcome for all humanity.”