Warming linked to stronger hurricanes

I still think it's suspicious that they always pull 1970 out to compare against. The hurricane seasons are cyclical and the early 70s were like the all time low in recorded hurricane activity. The late 50's and 60's had much more hurricane activity than the early 70's. The late 40's and early 50's were below average, but not as low as the 70's, and the 30s and early 40s were above average.

They've been telling us since the mid 90's that we have entered the above average portion of the hurricane season cycle. So comparing the last couple of years to 1970 is like comparing August temperatures to January temperatures. It makes much more sense to compare August temperatures to August temperatures.

They should instead by comparing our current peak to the peaks in the 60s and the early 40s. I think you would still see an upward trend in hurricane strength, but it would not be nearly as dramatic as it is when they compare to 1970. (Which is likely why they always compare against 1970)

I'm not sure if the IPCC linked global warming to Katrina and Rita's strengths, but I know some of the news articles at least have. It should be noted that both Katrina and Rita were barely category 1 hurricanes when they approached Florida after crossing the global warming heated waters of the Atlantic. It was when then entered the Gulf of Mexico and passed over the Gulf Loop Current that they changed in to monsters. As has every hurricane in recorded history that enters the Gulf in the middle of the season when large warm water eddies form around the Gulf Loop Current.

 

I'm not so sure the science is very clear, as noted here

Australia's Neville Nicholls, who was one of the authors responsible for drafting the language on tropical cyclones:

"I was disappointed that after more than two years carefully analysing the literature on possible links between tropical cyclones and global warming that even before the report was approved it was being misreported and misrepresented. We concluded that the question of whether there was a greenhouse-cyclone link was pretty much a toss of a coin at the present state of the science, with just a slight leaning towards the likelihood of such a link. But the premature reports suggested that we were asserting the existence of much stronger evidence. I hope that when people read the real report they will see that it is a careful and balanced assessment of all the evidence."

And here where Chris Landsea resigned from the IPCC review ...

"I found it a bit perplexing that the participants in the Harvard press conference had come to the conclusion that global warming was impacting hurricane activity today. To my knowledge, none of the participants in that press conference had performed any research on hurricane variability, nor were they reporting on any new work in the field. All previous and current research in the area of hurricane variability has shown no reliable, long-term trend up in the frequency or intensity of tropical cyclones, either in the Atlantic or any other basin. The IPCC assessments in 1995 and 2001 also concluded that there was no global warming signal found in the hurricane record.

Moreover, the evidence is quite strong and supported by the most recent credible studies that any impact in the future from global warming upon hurricane will likely be quite small. The latest results from the Geophysical Fluid Dynamics Laboratory (Knutson and Tuleya, Journal of Climate, 2004) suggest that by around 2080, hurricanes may have winds and rainfall about 5% more intense than today. It has been proposed that even this tiny change may be an exaggeration as to what may happen by the end of the 21st Century (Michaels, Knappenberger, and Landsea, Journal of Climate, 2005, submitted)."

and goes on to say...

"The IPCC leadership saw nothing to be concerned with in Dr. Trenberth's unfounded pronouncements to the media, despite his supposedly impartial important role that he must undertake as a Lead Author on the upcoming AR4... I personally cannot in good faith continue to contribute to a process that I view as both being motivated by pre-conceived agendas and being scientifically unsound. As the IPCC leadership has seen no wrong in Dr. Trenberth's actions and have retained him as a Lead Author for the AR4, I have decided to no longer participate in the IPCC AR4."