A new study says human-caused climate change made Atlantic hurricanes about 18 mph stronger in the last six years. Wednesday's study says most storms gained so much strength due to warmer waters from climate change that they jumped an entire hurricane category, which means much more damage caused. Study authors say climate change goosed this year's killer hurricanes significantly. They say it boosted the winds of Beryl by 18 mph, Helene by 16 mph and Milton by 24 mph. Three of the storms studied jumped two categories in intensity including this month's Rafael.
