No, no.  I think you misunderstand my point:

I'm not saying that global warming won't cause more severe hurricanes.  I'm not even saying that it won't cause more hurricanes of whatever strength (though, like you said, it may not).

I'm just saying that the climatologists don't believe the current hurricane season's severity may be attributed to Global Warming.

In other words, global warming may severely impact our environment (it already is doing so, I believe), but this hurricane season is not the proof many people think it might be.  This season's severity is well-understood in light of the normal multi-decadal activity cycle.  Any influence from global warming is minor by comparison -- minor enough that we can't extract it from the pronounced impact of the multi-decadal cycle.

gunnk wrote:
"This season's severity is well-understood in light of the normal multi-decadal activity cycle.  Any influence from global warming is minor by comparison -- minor enough that we can't extract it from the pronounced impact of the multi-decadal cycle."

I made a link to Real climate where they discuss the relation between Global Warming and Hurricanes. They discuss mostly the Emanuel (2005) article from Nature. You can go to figure 2 at http://www.realclimate.org/index.php?p=181#comments

When you look at the figure 2 that it is a measure of total power dissipated annually by tropical cyclones in the North Atlantic (the power dissipation index "PDI") compared to September tropical North Atlantic SST (from Emanuel, 2005) you can note some interesting things:
1- there is a multi-decadal cycle;
2- there is a surge at hurricane activity that go ABOVE the multi-decadal cycle AFTER 1995.

Any statistical test will show that the hurricane activity after 1995 is ABOVE the normal and cannot be expected from the multi-decadal cycle. If you don't belive me, just believe at your EYES. LOOK THE FIGURE 2.

If you look the figure 2 it is EVIDENT that this season hurricane's activity CANNOT be explained by multi-decadal acrivity cycle and that any influence from Grobal Warming ISN'T a MINOR influence. But don't belive me, just go look the figure 2 http://www.realclimate.org/index.php?p=181#comments and come to your own conclusions. Just learn to think.

The REAL data is there. And IMHO the real data contradict gunnk opinion that "this season's severity is well-understood in light of the normal multi-decadal activity cycle" and that the Global Warning influence is "minor".

João Carlos

sorry my bad language, my native language is portuguese.

I still believe you have to look at more data over a greater time frame to determine the degree to which change is occurring.  Look at the data on historical hurricane strikes on the United States for example:

http://www.nhc.noaa.gov/pastdec.shtml

From this historical data there is no sign of a trend.  I know that the data set is NOT complete for all storms (only those that hit the U.S.), but it gives a good sample as a quick check for historical trends.

For the moment, I will continue to stand by the NWS statement that the effect of the normal hurricane cycles currently outweigh the effect of global warming on the current season.

Again, this is NOT an attempt to disparage the reality of global warming.  I'm just saying that we should not readily attribute the current season's ferocity to global warming if other, known causes provide a satisfactory explanation.

There is ample evidence of global warming elsewhere in the climatological data.  We don't need to try to point to dramatic examples which may prove unfounded.  To do so undermines attempts to educate the public and policy-makers as to the reality of the problem.  It moves the debate from science to advocacy.

I'm afraid you and I'll will have to respectfully disagree.  Contrary to your comments, I do know how to think.  I hold a degree in physics and worked for several years as a member of the Indoor Air Pollution research team at the U.S. EPA.  I just don't see the same pattern that you do -- at least not one that seems to hold up over longer time periods.  Therefore, in absence of the trend which you perceive, we reach different conclusions.


I'm not saying that global warming won't cause more severe hurricanes.  I'm not even saying that it won't cause more hurricanes of whatever strength (though, like you said, it may not).

I'm just saying that the climatologists don't believe the current hurricane season's severity may be attributed to Global Warming.


I think that you misspoke because those two paragraphs are conflicting.  Perhaps you meant, "I'm just saying that the climatologists don't believe the current hurricane season's frequency may be attributed to global warming.  In my pointy little head I equate hurricane severity with intensity.
No conflict.  I'm not speaking of the severity of the hurricanes, but of the severity of the season.

The severity of the season is a composite of the frequency and intensity of the individual storms.