UPDATE: I emailed Judith Curry, the first author on the BAMS paper, pointing out the double listing of 1994 and requesting her 1970 - 2005 data by year by basin by hurricane category, which should allow me to resolve some oustanding questions. (volokh.com)
Although this is a different metric from the one used by the G.F.D.L. group, who showed results in terms of hurricane categories, their results are fully consistent with the results of the 2008 paper. (dotearth.blogs.nytimes.com)
Figure 3: Human influence on hurricane proportions in the highest (Category 4 - 5) and lowest (Category 1 - 2) Saffir — Simpson hurricane categories (skepticalscience.com)