In order to make informed, risk-based decisions, policymakers must have information not only on probable events, but also on the worst (if less probable) scenarios. The interconnectedness of climatic systems makes assessing the social impacts of those events tricky, however.

Two studies in this issue use the concept of 'tipping points' to assess optimal policy responses in the face of uncertainty around the nature and timing of extreme events, and the way they interact.

Derek Lemoine and Christian Traeger (see page 514) analyse the impact of three different tipping points occurring at unknown thresholds. They show that because the occurrence of one climatic tipping point affects the chances of another happening, this creates a 'domino effect', almost doubling today's optimal carbon price. Yongyang Cai, Timothy Lenton and Thomas Lontzek model the impact of five tipping points (see page 520), and suggest the interaction of these impacts means the social cost of carbon increases as much as eightfold.

Although not an entirely new endeavour — some leading integrated assessment models have already adjusted their calculations to account for the impact of such 'discontinuities' — both pieces of research suggest the same course of action: risk-averse policymakers should support efforts to significantly curb greenhouse gas emissions in the short term (see the News & Views by Frederick van der Ploeg on page 442).

Such a risk-averse strategy also emerges as a sensible option when looking at impacts beyond tipping points. Research by Simon Dietz and colleagues offers a first estimate of the potential impact of climate change on the value of financial assets (Nature Clim. Change http://doi.org/bd4s; 2016). They suggest that around 1.8% or US$2.5 trillion of the world's financial assets could be at risk from business-as-usual emissions. But the devil is in the detail (or the tail of the probability distribution, in this instance). At the 99th percentile, the value of assets at risk is closer to US$24 trillion, illustrating the potential scale of the risk.

This suggests not only that investors should see climate change as a serious threat to wealth (see S. Fuss, Nature Clim. Change http://doi.org/bd4t; 2016), but that they must decide exactly how much risk they are willing to bear. This holds for decision-makers across the board: whatever happens, they have been warned that it was at least a possibility, at a given probability.