Earth is approaching an environmental tipping point

In 2024, we emitted more greenhouse gases in our atmosphere in a single year than any previous year. The increase from 2023 was small (0.8%), but global emissions continue to rise, even though science tells us we should have bent the global emissions curve. decreasing by 2020.

Emissions in our atmosphere are at work, warming the planet, acidifying our oceans and leading to climate-fueled disasters: heat waves, fires, floods, droughts and storms. For some climate impacts, devastation can be followed by careful recovery work. But for many natural systems, like our tropical coral reefs, the stress we impose on them is reaching the stage of permanent decline and, eventually, collapse.

As we approach 1.5 degrees Celsius of global warming – the globally agreed limit of the Paris Agreement –we risk triggering tipping points. They are sleeping giants who, in their healthy state, alleviate stress and cool the planet; systems with thresholds that, once crossed, lead to irreversible changes, ranging from mitigation to amplified stress, causing a loss of resilience of the planet and accelerating the pace of change.

Once tipping points are crossed, there is also a significant risk of dangerous cascades, where the first set of tipped systems has ripple effects on other tipping elements, pushing them beyond their thresholds, triggering a sequence of dominoes and further increasing the likelihood that Earth will move away from its stable state.

Many tipping points are now well known: the Amazon rainforest, the Greenland ice cap, the Southern Atlantic overturning circulation (or AMOC). But science continues to study and clarify at what precise level of warming they will pass their tipping point.

However, for some systems, we have much higher certainty. Tropical coral reef systems – the tropical rainforests of the ocean – are famous for their biodiversity, their unimaginable richness in color and life, being the breeding ground for myriad fish species and providing livelihoods for more than 400 million people. They also risk being one of the first ecosystems we lose completely to climate change if we don’t see a step change in measures to reduce our emissions.

It would be devastating. In addition to their unique environmental importance, coral reefs provide the ecological basis for many sectors of the global economy, including tourism and fisheries, worth tens of billions of dollars. They are also vital natural protection for many coastal regions against storms and erosion.

The world’s largest coral reef and richest marine ecosystem on the planet – Australia’s Great Barrier Reef –experienced another mass bleaching event in 2025. Bleaching occurs when corals expel algae in their system and turn ghostly white. Corals are animals living in symbiosis with algae and, although they can survive bleaching events, they need time to recover. However, the Great Barrier Reef also experienced one in 2024. And in 2022, 2020, 2017 and 2016.