World reaches first climate tipping point – widespread mortality of coral reefs

“We are rapidly approaching multiple Earth system tipping points that could transform our world, with devastating consequences for people and nature. This demands immediate, unprecedented action from leaders at COP30 and policymakers worldwide,”
says Professor Tim Lenton from the Global Systems Institute at the University of Exeter, a longtime Centre collaborator.

The second Global Tipping Points Report finds that warm-water coral reefs – on which nearly a billion people and a quarter of all marine life depend – are now passing their tipping point. Widespread dieback is occurring, and unless global warming is reversed, extensive reefs as we know them will be lost. However, small refuges may survive and must be protected.

Authored by 160 scientists from 87 institutions in 23 countries, the report warns that the planet is dangerously close to triggering other catastrophic tipping points – from melting ice sheets to Amazon rainforest dieback and the collapse of key ocean currents.

“This demands immediate, unprecedented action from leaders at COP30 and policymakers worldwide,” repeats Tim Lenton.

Solar and wind: Positive tipping points crossed

The report also highlights progress on positive tipping points – and opportunities for a cascade of positive change.

Positive tipping points have already been crossed in solar PV and wind power globally, as well as in the adoption of electric vehicles, battery storage, and heat pumps in leading markets. Coordinated policy action, it says, can trigger further transformative change across sectors and societies.

“There has been a radical global acceleration in some areas, including the uptake of solar power and electric vehicles. But we need to do more – and move faster – to seize positive tipping point opportunities. By doing so, we can drastically cut greenhouse gas emissions and tip the world away from catastrophic tipping points and toward a thriving, sustainable future,” says Lenton.

Equity at the heart of transformation

Centre researcher Dr. Laura Pereira served as the “equity and justice” liaison for the report’s Risks chapters and also contributed to the Human Rights chapter together with former Centre MSc student Ida Edling. Their work highlights that climate tipping points are deeply intertwined with social justice and human rights.

“Whilst we are entering an unprecedented phase of human-induced change to the planet, there remains time to act and to create a more sustainable and just future for all. The findings of this report require a strong reckoning with our current social and economic systems, which have led to this moment of potentially imminent cascading crises across our planet and societies, whilst offering some of the transformative solutions we must undertake to enable a more just and sustainable future,” says Dr Pereira, adding:
“We cannot address the climate crisis by perpetuating the same systems of injustice and oppression that caused it in the first place - we need deeper, more equitable solutions that allow a sustainable future for both people and planet.”

From crisis to transformation

The report calls on global leaders ahead of COP30 in Brazil to embed tipping point science into governance, economic planning, and adaptation policies. Researchers are working with Brazil’s COP30 Presidency to ensure that tipping points are included on the summit’s agenda.

“Current policy thinking doesn’t usually take tipping points into account. Tipping points present distinct governance challenges compared to other aspects of climate change or environmental decline, requiring both governance innovations and reforms of existing institutions,” says report contributor Dr Manjana Milkoreit from the University of Oslo.

Dr Mike Barrett, Chief Scientific Adviser at WWF-UK and co-author of the report, adds that the findings are “incredibly alarming.”

“That warm-water coral reefs are passing their thermal tipping point is a tragedy for nature and for the people who rely on them for food and income.

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