Tropical storms have been migrating northwards and southwards towards the poles for the past 30 years, a paper in Nature says. People are becoming less likely to face the worst of a hurricane or typhoon if they live close to the Equator, and more likely if they live on the edges of the tropics. The storms are reaching their maximum intensity 52-63km further north and south every decade. The paper, led by the US agency Noaa, underlines a previous finding that the area defined as the Tropics is clearly expanding. The researchers believe humans are influencing the changes – with climate change, ozone depletion and aerosols playing a part. They cannot yet be certain which factor is most significant. More