The 2005 North Atlantic hurricane season was the most active in recorded history, and caused an unprecedented level of damage.
Global warming accounted for around half of the extra hurricane-fueling warmth in the waters of the tropical North Atlantic in 2005, while natural cycles were only a minor factor.
… The study contradicts recent claims that natural cycles are responsible for the upturn in Atlantic hurricane activity since 1995. It also adds support to the premise that hurricane seasons will become more active as global temperatures rise.
Some background: Last year, sea-surface temperatures in the tropical Atlantic “were a record 1.7° F above the 1901-1970 average.”
Previous studies had suggested that the more intense hurricane activity was largely due to a 60-to-80-year natural cycle in sea-surface temperatures. But according to the study released today, less than .2° F of the rise was due to this natural cycle. Global warming, on the other hand, caused roughly half (about 0.8° F) of the rise, more than any other factor.