“The climate debate underestimates the risk of catastrophic outcomes”

Climate policy must not be based only on the most likely scenario. Even unlikely events must be taken into account if we want to make good decisions, including decisions about which risks we can, and cannot, accept. That was the main message when philosopher Gustaf Arrhenius, CEO of the Institute for Futures Studies, spoke about climate, risk, and future generations at the Rausing Symposium 2026, organized by the Royal Physiographic Society in Lund.

In the lecture, he argued that decision-makers must consider events even when they have a low probability, if those events could have extreme and catastrophic consequences.

A central point is that climate models and economic analyses often focus too much on what is likely to happen. According to Gustaf Arrhenius, this is insufficient.

– Focusing on what is likely to happen is a very poor basis for decisions. And most people do not make decisions this way either. It is likely that your house will not burn down, but you still get fire insurance. Unlikely events can matter for decisions if the consequence is a catastrophe. It is the same with the climate. I think we need to bring this more fully into the climate debate and openly discuss which risks we are willing to take, and which we cannot accept, said Gustaf Arrhenius.

At the same time, he rejected the idea that researchers should downplay serious risks in order not to frighten the public. A new study conducted at IFFS gives no support to that idea.

– It is often said that we should be careful about what we say to the public because people may become so frightened that they stop acting. But our data show that support for climate action actually increases with the degree of concern. We see no paralyzing effect of climate worry, said Gustaf Arrhenius.

The study is based on data from 14 countries and around 9,000 people. Among those who were most worried, only three percent had low support for climate measures. Among those who were least worried, 41 percent had low support for climate measures.

Gustaf Arrhenius also spoke about why moral philosophy has a place in the climate issue. The climate crisis is not only about scientific forecasts, but also about values: what counts as dangerous, how costs should be distributed between countries, and what responsibility people alive today have toward those who have not yet been born.

– Most people who will ever exist will live in the future — and we can affect their life prospects enormously, says Gustaf Arrhenius.