Coral die-off marks Earth's first climate 'tipping point', scientists say

[Submariner]

A surge in global temperatures has caused widespread bleaching and death of warm-water corals around the world.


Vast expanses of coral in Australia’s Great Barrier Reef have died as a result of extremely high water temperatures.

Surging temperatures worldwide have pushed coral reef ecosystems into a state of widespread decline, marking the first time the planet has reached a climate ‘tipping point’, researchers announced today.

They also say that without rapid action to curb greenhouse-gas emissions, other systems on Earth will also soon reach planetary tipping points, thresholds for profound changes that cannot be rolled back.

“We can no longer talk about tipping points as a future risk,” says Steve Smith, a social scientist at the University of Exeter, UK, and a lead author on a report released today about how close Earth is to reaching roughly 20 planetary tipping points. “This is our new reality.”

Temperature spike

Led by Smith and other scientists at the University of Exeter, the report assesses the risk of breaching tipping points such as ice-sheet collapse, rising seas and dieback of the Amazon rainforest. It also discusses progress towards various positive tipping points focused on social and economic change, such as the adoption of clean energy.

The group’s first such assessment, released less than two years ago, raised alarms but did not officially declare that any climate tipping points had been reached. In the past few years, however, global temperatures have surged, sparking concerns among some scientists that global warming is accelerating and could lead to even more widespread impacts in the coming decades than the changes that have already been recorded.

The impact on coral reefs has been particularly severe in the past two years , pushing these ecosystems to their tipping point, the researchers say. The warming waters have caused corals across the globe to bleach, a process that occurs when the organisms expel the symbiotic algae that provide them with nutrients, oxygen and vibrant colours. The fourth global bleaching event in the past few decades began in January 2023, and researchers estimate that it has affected more than 84% of the planet's coral ecosystems.

https://www.nature.com/articles/d41586-025-03316-w

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If you're a scuba diver who enjoys coral reef dives, Get to your favorite spot soon, because in a decade or two healthy coral reefs will only be a memory.