IPCC Hurricane Conclusions Called Into Question
And the hits keep on coming. Now it is hurricane data being called into question:
More trouble looms for the IPCC. The body may need to revise statements made in its Fourth Assessment Report on hurricanes and global warming. A statistical analysis of the raw data shows that the claims that global hurricane activity has increased cannot be supported.
Dr. Les Hatton says he is neither “a warmist nor a denialist”, but a scientist. And as a scientist he took a look at the IPCC’s claims about hurricanes and found them wanting:
Hatton performed a z-test statistical analysis of the period 1999-2009 against 1946-2009 to test the six conclusions. He also ran the data ending with what the IPCC had available in 2007. He found that North Atlantic hurricane activity increased significantly, but the increase was counterbalanced by diminished activity in the East Pacific, where hurricane-strength storms are 50 per cent more prevalent. The West Pacific showed no significant change. Overall, the declines balance the increases.
“When you average the number of storms and their strength, it almost exactly balances.” This isn’t indicative of an increase in atmospheric energy manifesting itself in storms.
Says Hatton, after running his statitistical analysis and reading the IPCC report, he found it’s conclusions could not be supported by the data:
The IPCC continues: “It is more likely than not (> 50%) that there has been some human contribution to the increases in hurricane intensity.” But, as Hatton points out, that conclusion comes from computer climate models, not from the observational data, which show no increase.
“The IPCC goes on to make statements that would never pass peer review,” Hatton told us. A more scientifically useful conclusion would have been to ask why there was a disparity. “This differential behaviour to me is very interesting. If it’s due to increased warming in one place, and decreased warming in the other – then that’s interesting to me.”
It would be interesting to others as well since it might indicate the observed warming was a result of regional weather, not global warming. Hatton has put his work on his personal web site (you can see it here) and issued an open invitation to prove his analysis wrong. Al Gore has said he’ll get right on it.