Fires, floods, polar vortexes and hurricanes — every season brings another disaster seemingly linked to climate change. But natural disasters happened before climate change, too. So how are we supposed to know which disasters are fated because of the stars, and which are fated because of 100 years of global CO2 emissions?
Since the calamities aren’t going to stop anytime soon, we figured it’d be helpful to give you a guide for how to think empirically about disaster news in a climate change era. We asked some climate scientists what they think the headlines get wrong or leave out. They offered four tips for thinking about natural disasters and climate change — tips they say can make the difference between feeling hopeless about the future and finding ways to change it.
1) No disaster is actually “natural”
Or, at least, not purely natural, said Chris Field, an environmental scientist who was co-chair of an Intergovernmental Panel on Climate Change working group. He’s literally written the book (well, the report) on climate change and disasters, and said that the “disaster” label is about what happens when nature and people meet — not what nature does, alone. A hurricane that strikes a sparsely populated strip of coastline isn’t the same as one that hits a major metropolis. A heat wave in a region that’s used to dealing with high temperatures is much less of a disaster than the same heat in a place where almost no one has central air. Thinking about the “natural” and the “disaster” as two separate things is important, experts told me, because it changes the way we respond. If our risks are about more than just what the climate and the weather does, that means there are more ways to reduce our risks. It’s not an all-or-nothing situation where we have to either stop climate change or encounter doom.
2) Climate change is “a” cause of disasters, not “the” cause
Behind every natural event that becomes a disaster is a tangle of causes — some natural, some man-made. Climate change might be a part of it, but it’s never the only thing going on. “When I look at any of these events and see the headlines, it’s almost always a situation where [the disaster] is caused by natural variability … and the climate change part of it is making it worse,” said Lisa Goddard, director of the International Research Institute for Climate and Society at Columbia University. For example, drought in the West is linked to an increased risk of wildfire, but the droughts we’ve seen over the last couple decades are natural cycles, Goddard said. Combine those with climate-change induced higher average temperatures, though, and you’ve got a natural problem made bigger by human-caused change. This kind of thing is what makes makes climate communication messy. You want people to take the impacts of climate change seriously. At the same time, the risks of a natural disaster are about more than just carbon dioxide concentrations in the atmosphere.
3) Don’t ask “how much,” ask “how likely”
It’s almost impossible to know how much of a disaster is caused by climate change. And that’s the wrong question to even ask, Goddard said. Instead, try and think about whether climate change has increased the likelihood or severity of a type of disaster overall, said Melissa Allen-Dumas, a researcher at the Oak Ridge National Laboratory who focuses on climate change and critical infrastructure. That’s because the answer to that question actually has an impact on how people and communities respond after a disaster strikes. Knowing whether or not a particular hurricane would have happened if not for climate change doesn’t necessarily affect how you rebuild. Knowing that climate change is raising the sea level and increasing the likelihood of coastal flooding, however, should.
4) When all else fails, think in terms of vulnerability
Disasters don’t take place in a vacuum — their devastation depends on the vulnerability of the communities they affect. The consequences of a drought and high temperatures will be less severe if forests have been managed in a healthy way and the wilderness isn’t full of aging power lines. When you read about climate change disasters, pay attention to the issues that make communities more or less vulnerable. Those vulnerabilities are, in some cases, preventable ones. The way you think about a given disaster (and future possible disasters) changes if you know that.
Understanding vulnerability is also important to understanding the global impacts of climate change. When we talk about developing countries being more at risk from climate change, what we’re talking about is the vulnerability — and whether or not they have the resources to adapt. If you look purely at the monetary value, somebody who owns a house in Malibu may be more at risk from a climate change-associated natural disaster than a farmer in Bangladesh. But ultimately, Field said, it’s the farmer who has more to lose. Insurance, having extra money in the bank, having access to emergency services, and even just having the ability to move someplace else — all those things affect vulnerability, which, in turn, affects how big of a disaster a natural event turns out to be.
Maggie Koerth is a senior science writer for FiveThirtyEight. @maggiekb1