In the last two decades, natural disaster costs worldwide went from about $100 billion per year to almost twice that amount. That’s a huge problem, right? Indicative of more frequent disasters punishing communities worldwide? Perhaps the effects of climate change? Those are the questions that Congress, the World Bank and, of course, the media are asking. But all those questions have the same answer: no.
When you read that the cost of disasters is increasing, it’s tempting to think that it must be because more storms are happening. They’re not. All the apocalyptic “climate porn” in your Facebook feed is solely a function of perception. In reality, the numbers reflect more damage from catastrophes because the world is getting wealthier. We’re seeing ever-larger losses simply because we have more to lose — when an earthquake or flood occurs, more stuff gets damaged. And no matter what President Obama and British Prime Minister David Cameron say, recent costly disasters are not part of a trend driven by climate change. The data available so far strongly shows they’re just evidence of human vulnerability in the face of periodic extremes.
To identify changes in extreme weather, it’s best to look at the statistics of extreme weather. Fortunately, scientists have invested a lot of effort into looking at data on extreme weather events, and recently summarized their findings in a major United Nations climate report, the fifth in a series dating back to 1990. That report concluded that there’s little evidence of a spike in the frequency or intensity of floods, droughts, hurricanes and tornadoes. There have been more heat waves and intense precipitation, but these phenomena are not significant drivers of disaster costs. In fact, today’s climate models suggest that future changes in extremes that cause the most damage won’t be detectable in the statistics of weather (or damage) for many decades.