This report reviews evidence that overshooting 1.5°C may push the earth over several tipping points, leading to irreversible and severe changes in the climate system. If triggered, tipping point impacts will rapidly cascade through socio-economic and ecological systems, leading to severe effects on human and natural systems and imposing important challenges for human adaptation. Of particular concern are the likely collapse of the West Antarctic and Greenland ice sheets and the abrupt melting of permafrost grounds in the Arctic, which would result in additional sea-level rise and greenhouse gas releases, leading to more warming.

Based on the most recent science and consultations with renowned experts, Climate Tipping Points: Insights for Effective Policy Action argues that it is no longer appropriate to consider the risk of crossing tipping points as low-probability. Overshooting 1.5°C may likely lead to irreversible and severe impacts, which must be avoided, heightening the urgency to drastically reduce emissions within this decade. The report calls for a shift in how tipping points are treated in climate policy today and provides recommendations on how climate risk management strategies can better reflect the risks of tipping points in the areas of mitigation, adaptation and technological innovation.