Changes in Atlantic Major Hurricane Frequency Since the Late-19th Century

Abstract Atlantic hurricanes are a major hazard to life and property1,2,3, and a topic of intense scientific interest4,5,6. Historical changes in observing practices limit the utility of century-scale records of Atlantic major hurricane frequency7-13. To evaluate past changes in frequency, we have here developed a homogenization method for Atlantic hurricane and major hurricane frequency over 1851-2019. We find that recorded century-scale increases in Atlantic hurricane and major hurricane frequency, and associated decrease in USA hurricanes strike fraction, are consistent with changes in observing practices and not likely a true climate trend. After homogenization, increases in basin-wide hurricane and major hurricane activity since the 1970s14-15 are not part of a century-scale increase, but a recovery from a deep minimum in the 1960s-1980s. These results support the notion that internal climate variability and aerosol-induced mid-to-late-20th century major hurricane frequency reductions16-24 have probably masked century-scale greenhouse-gas warming contributions to North Atlantic major hurricane frequency.