Meanwhile, natural climate variability independent of climate change is likely what's boosting the number of big storms in recent years. Robichaud says that includes an Atlantic hurricane "cycle": "We're in a period of high activity right now." That period started in 1995 and is expected to last 20 or 30 years before being followed by 20 or 30 years of less hurricane activity. In fact, there are so many factors that contribute to a storm, he says, that "it's tough to tie any one event to climate change." - cbcnews