Katharine Mach and Miyuki Hino write: As scientists who study climate risks and how societies can respond, we have been jolted to think hard about our best understanding of why disasters like these occur, how a changing climate cranks up the odds and what we might do differently.

The answer, for scientists and everyone else who has been watching, is not to say definitively and dismissively, “This is the result of climate change” or “There’s nothing we can do.” It’s a chance to understand what is actually happening to the climate and all the ways human behavior leads to — and can mitigate — future disaster.

We start with two premises. Climate change doesn’t cause extreme events. It amplifies them. And in any weather-related calamity, our susceptibility to harm is, at its root, constructed by ourselves.

On the climate side of risk, we have unambiguous evidence that the hazards are changing. Our emissions of heat-trapping gases have already increased the likelihood and severity of heat waves, extreme rainfall and storm surges. Much of the world’s population occupies places susceptible to this kind of extreme weather that will increasingly be exacerbated by the changing climate.

Scientists can now even evaluate how much climate change has increased the odds of individual extreme events, including rainfall and flooding. In the weeks and months to come, we will surely see specific analyses of climate change’s role in the flooding in both Texas and South Asia. Put simply, a warmer atmosphere can hold more water, increasing the potential for heavy downpours. Storm surge now occurs on top of sea level rise, increasing flooding risk. And warmer oceans can produce more intense hurricanes, as has occurred in the North Atlantic and the Gulf. [Continue reading…]