WASHINGTON (AP) — Tropical cyclones worldwide are moving out of the tropics and more toward the poles and generally larger populations, likely because of global warming, a surprising new study finds. Atlantic hurricanes, however, don’t follow this trend.

While other studies have looked at the strength and frequency of the storms, which are called hurricanes in North America, this is the first study that looks at where they are geographically when they peak. It found in the last 30 years, tropical cyclones, regardless of their size, are peaking 33 miles farther north each decade in the Northern Hemisphere and 38 miles farther south each decade in the Southern Hemisphere.