Climate scientists are warning that global warming could trigger a cascade of “tipping points” that threaten to plunge our planet into chaos. But what exactly are tipping points, what happens if we cross them, and how can we avoid them?
What are tipping points?
Scientists have identified many potential tipping points, but some of the big ones include the collapse of polar ice sheets, thawing of carbon-trapping permafrost and widespread forest dieback. Leaving climate change unchecked increases the risk of passing these tipping points and —as our planet’s systems are interconnected — this could lead to a cascading domino effect whereby other tipping points are also triggered.
“Crossing one tipping point could set off a cascade of other tipping point crossings with the majority of interactions being destabilizing,” climate researchers wrote in the 2025 state of the climate report, published Oct. 29 in the journal BioScience. “In the worst case, this could push the climate system onto a hothouse Earth trajectory. This trajectory would lead to a fundamentally different planet with devastating impacts on natural systems and humanity.”
Feedback loops
Humans are warming the planet by releasing vast quantities of greenhouse gases into the atmosphere. These gases, like carbon dioxide (CO2) and methane (CH4), absorb outgoing radiation, trapping heat and pushing up global average temperatures.
The increased emissions primarily come from us burning fossil fuels like coal, oil and natural gas for energy. However, there are also natural processes that emit greenhouse gases — as well as those that absorb greenhouse gases. Warming can unlock, enhance or disrupt these natural processes to further compound the rate at which Earth heats up.
Tipping points are driven by these feedback loops, with greenhouse gas emissions leading to warming that unlocks even more gases, triggering even greater warming. For example, as the planet gets hotter, scientists expect the ocean to absorb less CO2 because gases don’t dissolve as well in warmer waters, which means more CO2 makes it into the atmosphere, further warming the ocean.
Permafrost thaw
A much prophesied tipping point scenario involves the thawing of permafrost (permanently frozen ground) in the Arctic. Huge quantities of carbon are locked away in permafrost soils, so as global temperatures rise and the permafrost thaws, more carbon would be released into the atmosphere, creating more warming and more permafrost thaw, and so on.
A 2024 study published in the journal PNAS found that permafrost dictates the flow of water, and its melting could lead to the formation and expansion of rivers, which in turn would release more carbon emissions.
Climate change is supercharged in the Arctic, where temperatures are warming around four times faster than the rest of the world. This accelerated warming, known as Arctic amplification, is driven by melting sea ice. Ice reflects more sunlight than land or water, so when climate change causes the Arctic’s sea ice to melt, the region absorbs more sunlight and warms up even faster than non-icy areas, according to the International Science Council.
Ice sheet collapse
Ice loss on the Greenland and West Antarctic ice sheets has accelerated since the 1990s as global temperatures increased. More ice loss means higher sea levels, which threaten coastal communities around the world. Research suggests these ice sheets are inching towards — and may have even already reached — tipping points that will cause them to collapse into the ocean.
Researchers aren’t sure how much more warming will result in ice sheets passing their tipping points. The threshold is unlikely to be apparent until after it has already been crossed. However, scientists have warned that humanity’s current plans for keeping warming in check might not be sufficient to prevent ice sheet collapse.
In 2015, world leaders signed the Paris Agreement, an international treaty that promised to limit global warming to preferably below 1.5 degrees Celsius (2.7 degrees Fahrenheit) and well below 2 C (3.6 F). A 2025 study published in the journal Communications Earth & Environment proposed that even warming of 1.5 C was too high for polar ice sheets. To make matters worse, the United Nations has just announced that we’re not meeting the 1.5 C target.
What makes tipping points like the Greenland Ice Sheet so concerning is their potential to impact other systems. Accelerated ice melt could be slowing down the Atlantic Meridional Overturning Circulation (AMOC), a major ocean current that acts as a conveyor belt, bringing warm water to the North Atlantic. Should the AMOC collapse, it could cause temperatures in parts of the Northern Hemisphere to plummet.
Amazon rainforest
The Amazon rainforest is sometimes referred to as “the lungs of the planet” — but this nickname is misleading. Even though forests like the Amazon naturally absorb CO2 (and convert it to oxygen as part of photosynthesis), the ocean has always been a much larger and more significant carbon sink. Furthermore, whatever “lungs” the Amazon might have are spluttering and failing.
A 2021 study published in the journal Nature found that the Amazon rainforest is releasing more carbon into the atmosphere than it’s removing. This reversal is largely driven by human activities, such as the lighting of fires to clear land for agriculture and industry. Fires contribute to and are fueled by climate change, which causes the forests to become hotter and drier. These conditions then make them more flammable, creating a destructive feedback loop.
Some scientists have warned that a combination of climate change and deforestation is forcing the Amazon to the brink of a tipping point, which could see it transform from lush tropical rainforest to a dier savanna habitat within a century. However, not all researchers agree with this assessment.
Avoiding devastation
The consequences of global warming are varied and complex, as illustrated by the uncertainty surrounding tipping point thresholds. However, the cause of the warming is simple, and so is the solution to keep climate change in check.
Humans are increasing global temperatures by pumping CO2 and other heat-trapping greenhouse gases into the atmosphere. The amount of global warming we get is proportional to the amount of carbon emissions, so to reduce the warming and its consequences, we simply need to cut emissions.
“Every year of delay locks in higher risks and costs,” William Ripple, a distinguished professor of ecology at Oregon State University and co-lead author of the 2025 state of the climate report, recently told Live Science. “We can limit the damage if we act like this is the emergency it truly is.”
