Assessments of climate-related hazards too often focus on indicators on spatial scales that are based on climate model grid points, such as the hottest day of the year to indicate change in extreme heat10 or the meteorologically most extreme events11. Instead, to help with reducing disaster impacts, it would be more informative to assess hazards at the temporal and spatial scales that are relevant from a risk and vulnerability point of view, such as looking at heatwaves that cross a particular temperature threshold in cities, on a day or a few days, rather than estimating country scale heat extremes. Spatial scales of assessment can make a big difference: the 2018 European heatwave has been estimated to have become 30 times more likely as a result of climate change – but the extreme heat over the 3 days when mortality was highest only became 2–5 times more likely in individual European cities12.
Climate science and attribution has an important role to play13, for example, in disentangling where human-induced climate change is a key driver of hazards14. This is important: where climate change has exacerbated risk, it is likely that the hazard will worsen over time, and past observations become increasingly less relevant. Climate change attribution must also be used to communicate which disasters today are partially or wholly a result of human-induced climate change.
In the wake of the 6th Assessment Report from Working Group I of the Intergovernmental Panel on Climate Change, there is opportunity to reflect and act. Disaster impacts can be reduced drastically. We must stop blaming Nature or the Climate for disasters, and put vulnerability and equity15 at the centre of proactive and engaging disaster laws and policies9. Such a basic conceptual re-orientation is a necessary starting point to identify and leverage structural, systemic and enabling solutions that transform societies to be more equitable and resilient in the long term.
