Over the past 30 years, the location where tropical cyclones reach maximum intensity has been shifting toward the poles in both the northern and southern hemispheres at a rate of about 35 miles, or one-half a degree of latitude, per decade according to a new study…published in Nature.
As tropical cyclones move into higher latitudes, some regions closer to the equator may experience reduced risk, while coastal populations and infrastructure poleward of the tropics may experience increased risk. With their devastating winds and flooding, tropical cyclones can especially endanger coastal cities not adequately prepared for them. Additionally, regions in the tropics that depend on cyclones’ rainfall to help replenish water resources may be at risk for lower water availability as the storms migrate away from them.
The amount of poleward migration varies by region. The greatest migration is found in the northern and southern Pacific and South Indian Oceans, but there is no evidence that the peak intensity of Atlantic hurricanes has migrated poleward in the past 30 years.
By using the locations where tropical cyclones reach their maximum intensity, the scientists have high confidence in their results…
Consistent with this poleward shift, many other studies are showing an expansion of the tropics over the same period since 1980…
The expansion of the tropics has been observed independently from the poleward migration of tropical cyclones, but both phenomena show similar variability and trends, strengthening the idea that the two phenomena are linked. Scientists have attributed the expansion of the tropics in part to human-caused increases of greenhouse gases, stratospheric ozone depletion, and increases in atmospheric pollution.
However, determining whether the poleward shift of tropical cyclone maximum intensity can be linked to human activity will require more and longer-term investigations.
The essential conservatism of real science – as opposed to the crap foisted on the public by fossil fuel profiteers and their flunkies is as clear as ever. This group of researchers record at least three apparent contributing causes in their study – and note that research continues.
Slugs like the Koch Bros. would rather research be halted and climate change be ignored.