Focus the sun’s beams on the tropical ocean at peak intensity. Add in warm, moist air. Stir the pot with the motion of the spinning globe. The results become the most powerful storms on Earth, whether they’re called hurricanes, typhoons, cyclonic storms or tropical cyclones. Climate change is making warm water, the fuel for storms, more abundant, and rising sea levels are making storm surge more destructive. Rapid development means that 3 billion people — roughly 40 percent of the world’s population — now live within 200 kilometers (124 miles) of a coastline; it’s projected that by 2050 more than 1 billion will live directly at the water’s edge. While the world’s governments wrangle over sweeping measures to limit global climate change, coastal communities face hard and very specific choices about where to fight to keep storm surges at bay, and where to let Mother Nature have her way.
Massive flooding and a high death toll from Cyclone Idai, which first made landfall in southeast Africa March 15, focused the world’s attention once more on such storms. More and more researchers are linking climate change to the severity of specific weather events. One study concluded that as much as 38 percent of the rainfall from Hurricane Harvey, which caused catastrophic flooding in Houston in 2017, was likely the result of global warming. A year later, voters in and around Houston elected by more than 4 to 1 to approve $2.5 billion in bonds for projects aimed at preventing a repeat of the flooding. Also in 2018, the U.S. Army Corps of Engineers held public hearings on a series of options to protect the New York City region from a repeat of the damage caused by what’s become known as superstorm Sandy in 2012. One proposal calls for harbor-wide storm-surge barriers to hold back the ocean, a project that could cost $30 billion. Similar barriers are already in place protecting London and coastal areas of the Netherlands.