From a reader:

Jonah –
As suggested I used your map of hurricanes from 1921-1940 on an unsuspecting liberal colleague. To my dismay, she was a bit more astute then maybe you and I were. She pointed out that while there were many hurricanes between those years, the majority were on the lower scale of the strength (1 and 2s), while presently we are experiencing more 3s, 4s, and 5s. She points out, accurately I may say, that hurricanes upgrade their strength based on water temps, which she claims to have risen due to global warning.
We need to come up with something better!
A Dismayed Cornerphile

Me: Well, this might help. We are almost done with 2005. The average number of major (cat 3, 4 or 5) hurricane strikes on the US per decade is 6. There were 10 during the 1940s.

Meanwhile, people should keep in mind that global water temperatures are rising, but the number of major hurricanes in other regions is not. If global warming explained the current spate of big hurricanes, there would be more in the South Pacific and elsewhere. It’s my understanding there haven’t been.