We are near tipping points that will make the climate crisis worse

William J. Ripple is a distinguished professor at Oregon State University and Director of the Alliance of World Scientists. Johan Rockström is a professor in Earth system science at the University of Potsdam and director of the Potsdam Institute for Climate Impact Research.

Several things concern climate scientists today. Despite policy commitments, the world is not reducing unsustainable pressures on the planet. Time is running out as we approach the halfway point of the decisive decade that will shape the future.

We have also underestimated the risks: warming is increasing faster than expected. If we cross ‘tipping points’, we enter a situation of accelerated change that is more dangerous than the extreme weather events that we are already facing today.

In our 2024 State of the Climate Report, we provide an update on the climate crisis, track Earth’s vital signs, and document how the frequency and intensity of extreme weather events have escalated at an alarming rate.

Devastating hurricanes, unrelenting heatwaves, catastrophic floods, and wildfires have ravaged communities across the globe. The once predictable rhythms of the natural world have been replaced by an unforgiving climate, where the boundaries between seasons blur, and the whims of nature become increasingly erratic.

Climate feedback loops add a sinister layer to this unfolding crisis. As the Arctic ice melts, reflective white surfaces are replaced by dark ocean waters, which absorb more heat and accelerate warming, resulting in further ice melting.

Similarly, thawing permafrost releases carbon dioxide and the potent methane, further exacerbating the greenhouse effect and thawing more permafrost.

Tipping points represent the most terrifying aspect of the climate crisis. These critical thresholds, once crossed, trigger irreversible changes in the Earth's systems. The collapse of the West Antarctic Ice Sheet, for instance, would result in several metres of sea-level rise. The dieback of the Amazon rainforest would unleash vast amounts of CO2 into the atmosphere.

Some of these tipping points are not distant threats but imminent dangers, poised to reshape our world in ways we can scarcely imagine. As vast regions become too hot to sustain life, we face the grim prospect of mass migrations and geopolitical instability. Despite having contributed little to climate change, the world’s poor face some of the greatest risks.

In defiance of repeated warnings from scientists, global fossil fuel consumption reached a record high last year. The clock is ticking, and the window for meaningful action is rapidly closing. In the words of Dr. Martin Luther King Jr., we must confront the “fierce urgency of now.”

This is not merely an environmental issue; it is an existential threat to our way of life. We must mobilise on an unprecedented scale, embracing renewable energy, prioritising social justice, rethinking our consumption patterns, and demanding bold action from our leaders.

Tipping points such as the Greenland Ice Sheet, the Atlantic Ocean circulation, and the Amazon rainforest are pivotal systems that, if destabilised, could trigger cascading and irreversible changes in the Earth system.

We must prioritise the protection and governance of critical climate tipping points as “global commons”.

That means acknowledging that they are shared resources, not owned or governed by any single nation, but collectively held and to be cared for by humanity. As such, they require coordinated global stewardship and dedicated governance regimes to ensure their resilience and stability.

To support this, governments must fulfill their legally binding commitments, signed by 195 countries, to maintain the 1.5 degree Celsius limit. They must accelerate the phase-out of fossil fuels as outlined in the Dubai statement, and update national climate plans according to the latest scientific findings.

The planetary climate crisis should also be established as a standing agenda item for the U.N. Security Council. Political leadership then needs to implement a global carbon price exceeding $100 per ton of CO2 – using those funds to support vulnerable communities and green energy transitions in developing countries.

And protecting all remaining intact nature is crucial, which means delivering on the global biodiversity framework. Nature serves as our resilience against climate extremes and acts as a vital carbon sink.

Let us not be the generation that stood idly by as the Earth descended into chaos. The stakes have never been higher, and the time for action is now.