Climate-related physical risks Changes are expected in the frequency, severity and geographical distribution of extreme weather events such as tropical cyclones and extreme rainfall and associated flooding or heat waves in the event that society fails to limit climate change to well below an increase of two degrees Celsius. Scientific consensus suggests society is likely to experience devastating impacts as a result of these changes. Current climate models, such as the International Panel on Climate Change (IPCC) model upon which Zurich bases its internal climate scenarios, indicate that physical climate-change risk will begin to rise more materially after the next two decades if left unmitigated.