Climate tipping points explained: which are we closest to?
Some parts of the climate system don't change gradually. Push them past a threshold and they keep changing on their own — for centuries or millennia. Several of those thresholds lie within the range of warming we are heading for.
By Andreas Marshall · Last reviewed 17 October 2026 · Every claim is linked to its source below.
The thresholds
In 2022, a team led by David Armstrong McKay reviewed more than 200 studies to estimate the warming level at which each tipping element is likely to be triggered. Dots show the best estimate; bars show the range of plausible thresholds.
Global tipping elements: warming threshold (°C above pre-industrial)
Data: Armstrong McKay et al. (2022), Table 1. “Today” = human-induced warming in 2024 (Forster et al. 2025). Current policies ≈ 2.8 °C by 2100 (UNEP 2025). Timescales show how long the change takes once triggered.
Regional tipping elements (°C above pre-industrial)
Already crossed? Coral reefs
The Global Tipping Points Report 2025concluded that warm-water coral reefs have passed their thermal tipping point. Since 2023 the world has seen the most extensive coral bleaching event on record. Without rapid cooling, the report says, widespread reef die-off is now expected — threatening the food and livelihoods of hundreds of millions of people.
Why it matters
At today's ~1.4 °C, five tipping elements are already within their uncertainty range. Between 1.5 °C and 2 °C, the best estimates for Greenland, West Antarctica, coral reefs and abrupt permafrost thaw are all reached. At the ~2.8 °C that current policies point towards, many more come into range.
Ice sheets take centuries to millennia to melt fully, so crossing a threshold is not an instant catastrophe. But it locks in long-term consequences — Greenland and West Antarctica together hold enough ice to raise sea level by about 10 metres. That is why scientists stress that every tenth of a degree matters, and why limiting the time spent above 1.5 °C reduces the risk.
Frequently asked questions
What is a climate tipping point?
A threshold beyond which a part of the Earth system changes in a self-sustaining way — continuing to change even if warming stops — often abruptly and irreversibly on human timescales. Examples include the collapse of ice sheets, dieback of the Amazon rainforest and the shutdown of major ocean currents.
Have any climate tipping points been crossed?
The Global Tipping Points Report 2025 concluded that warm-water coral reefs have passed their thermal tipping point, making them the first major tipping system to do so. It also found that parts of the polar ice sheets may already be past their thresholds.
How many tipping points are there?
Armstrong McKay et al. (2022) identified 9 global “core” tipping elements and 7 regional “impact” tipping elements. The Global Tipping Points Report assesses more than 25 systems.
Will the AMOC (Gulf Stream) collapse?
The IPCC finds the Atlantic Meridional Overturning Circulation is very likely to weaken this century, with medium confidence that it will not collapse abruptly before 2100. Some newer studies suggest a collapse could be more likely than previously thought; the 2022 assessment puts the threshold anywhere between 1.4 °C and 8 °C.
Can tipping points trigger each other?
Yes, that is a major concern. Melting Greenland ice freshens the North Atlantic and can weaken the AMOC, which in turn affects rainfall over the Amazon and West Africa. Such cascades make the risk of crossing several thresholds higher than the sum of individual risks.