Scientists confirm: Earth has passed the first global climate "tipping point"

Coral reef ecosystems have entered a state of widespread decline as global temperatures continue to soar, marking the planet has passed the first recognized "tipping point" in the climate system, according to a new study led by the University of Exeter in the UK. The report warns that if greenhouse gas emissions cannot be curbed quickly, other key systems of the Earth will gradually exceed the threshold of irreversible transformation.

The report systematically assesses the risks of about 20 Earth system tipping points, including ice sheet collapse, sea level rise and Amazon rainforest degradation. A sharp increase in global temperatures in recent years, compared with the first assessment two years ago, has prompted scientists to confirm that the first climate tipping point has been exceeded.

Coral reefs are among the hardest-hit ecosystems. Warming ocean waters are triggering global coral bleaching - a crisis that occurs when corals are exposed to heat stress and expel the symbiotic algae that provide them with nutrition and color. The fourth round of global bleaching events that began in January 2023 is estimated to have affected more than 84% of the world's coral reefs. The researchers pointed out that the increasing frequency and intensity of disturbance events are making it difficult to maintain the natural recovery cycle of corals, leading to ecosystem collapse.

Research and analysis show that even if future global warming can be stabilized at the 1.5°C target set by the Paris Agreement, coral reefs will continue to decline. To maintain a coral reef system with certain ecological functions, global warming needs to be further reduced to about 1°C above pre-industrial levels, which will inevitably rely on the application of large-scale carbon removal technologies in the future.

The study highlights that dealing with such irreversible tipping points poses a fundamental challenge to the current climate governance system. The international community needs to take governance actions commensurate with the severity of the crisis, immediately and drastically reduce emissions and accelerate the development of carbon removal technologies to prevent the loss of other critical ecosystems.