Studies that link global warming to an increase in hurricane ferocity might be full of hot air, according to a research paper that will be published Friday in a major scientific journal. The paper, co-written by Chris Landsea of the National Hurricane Center in West Miami-Dade, challenges earlier findings that hurricanes have grown more powerful in the last 30 years. It says those studies failed to account for technological improvements that now produce more accurate -- and often higher -- estimates of a storm's power than were available in the past. 'If you say, `Hey, the number of Category 4...