It was 1996. Florida was still recovering from hurricane Andrew, then the costliest storm ever to batter the United States. A consortium of reinsurers — the insurance companies for the insurance companies — had a question for Jeffrey Donnelly, a coastal geologist.How often have intense hurricanes occurred throughout history?That may sound like a simple question, but it isn’t. The first century of records from the Atlantic is a hodgepodge of ship logs and newspaper stories. Consistent cataloguing of tropical cyclones — hurricanes and typhoons — only began with the advent of satellites, around 1970. But Donnelly had different resources at his disposal: sediment cores, the metres-long plugs of compressed organic material extracted from coastal marshes, or what scientists call the “paleo record.” Trapped inside those sediment cores was evidence of the chaos wrought by major storms.The historical record — those logs and newspaper articles — “is far too small,” said Donnelly, a senior scientist at the Woods Hole Oceanographic Institution on Cape Cod in Massachusetts. “What the paleo record allows us to do is extend that back centuries and even millennia.” The reinsurers have since moved on. But 20 years later, Donnelly is still trying to reconstruct the ancient history of hurricanes, collecting sediment cores from Newfoundland to Brazil. This research — known as paleotempestology — is useful to scientists who want to understand why some years and decades are thrashed by frequent, destructive storms while others are quiet.Surprising insights about today’s hurricane patterns have already emerged. But one of the most critical questions is how those patterns might change, especially as the climate warms.“The biggest challenge is using what we know of just the past 100 years to say very much because it’s a very limited sampling of not only hurricanes but climate itse ...
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