Last month, the world was hit with the news that the first climate tipping point had been crossed: the widespread decline of warm-water coral reefs. With the world surpassing 1.2°C of warming, coral reefs are experiencing repeated mass bleaching events. This is where corals expel the symbiotic algae that provide their nutrients and colours, which increases their risk of starvation and disease.
This news was part of a wider report on the status of different climate tipping points, such as coral reef decline, melting ice caps, and Amazon forest dieback. The 2025 Global Tipping Points report warns that on the planet’s current trajectory of warming, we will be on track to reach more of these tipping points.
Reading this sobering news, it is easy to be gripped by fear— but what exactly is a climate tipping point, and is there anything we can do?
The term ‘tipping point’, first popularised by Malcolm Gladwell in his 2000 book of the same name, has been increasingly adopted by scientists to describe abrupt changes in the Earth’s system. Crossing a tipping point is like pulling out the final Jenga block that causes the tower to collapse.
Beyond this, all is not necessarily lost — but it becomes much more difficult, or even impossible, to restore the system to its original state.
Take the melting of polar ice sheets: even if we slow down or stop global warming, these ice sheets are unlikely to restore themselves without the help of another ice age, and geoengineering plans to restore the Arctic are controversial and expensive. Similarly, reforestation is underway in the Amazon, but planting and growing trees takes time, and the associated species extinction cannot simply be reversed.
This does not mean we should give up hope. Some experts have warned that the current news, in portraying coral reefs as ‘heading for collapse’, could lead people to give up on them altogether. In fact, coral reef conservation and minimising global warming are more important now than ever.
The Global Tipping Points report shares this emphasis on positive action. Like hope hidden at the bottom of this Pandora’s box of climate disasters, the report includes a section on positive tipping points, which can: “Trigger self-propelling change into a more sustainable state.”
An example of a positive tipping point is the decreasing cost of renewable energy, with solar and wind power now cheaper on average than the lowest-cost fossil fuels. The International Energy Agency (IEA) estimates that the growth in renewable energy over the next decade could meet nearly all the world’s growing electricity demands.
However, these positive changes need to be backed up by policy. Ten years ago, the Paris agreement set out the goal of limiting global warming to 1.5°C above pre-industrial levels— but the world is still on track to overshoot this by the end of the century. While the world is transitioning away from fossil fuels, this progress still appears to be too slow to meet international targets.
Among the sobering realities of climate change and the occasional glimmers of optimism, one common theme emerges: we, too, are a part of this Earth system. To cross a tipping point is not only harmful to coral reefs, ice sheets, or rainforests: these changes are far-reaching. Coral reefs, as well as being a vital part of the marine ecosystem, provide coastal protection and contribute to the fishing and tourism industries, and so the results of our actions must be considered in these further contexts.
Our own species cannot be disentangled from the climate, or from the many consequences of our own actions. But as the idea of a positive tipping point explores, these consequences do not always have to be negative. By working hand-in-hand with nature, we can achieve a better future for our planet.
