Re: Hurricane Intensity: An Example of Global Warming Alarmism

Now the other side that SST (sea surface temperature) increases from global
warming do indeed increase the intensity of hurricanes.

Deconvolution of the Factors Contributing to the Increase in Global
Hurricane Intensity *C. D. Hoyos,* P. A. Agudelo, P. J. Webster, J. A. Curry
*

To better understand the change in global hurricane intensity since 1970, we
examined the joint distribution of hurricane intensity with variables
identified in the literature as contributing to the intensification of
hurricanes. We used a methodology based on information theory, isolating the
trend from the shorter-term natural modes of variability. The results show
that the trend of increasing numbers of category 4 and 5 hurricanes
for the period
1970–2004 is directly linked to the trend in sea-surface temperature; other
aspects of the tropical environment, although they influence shorter-term
variations in hurricane intensity, do not contribute substantially to the
observed global trend.
School of Earth and Atmospheric Sciences, Georgia Institute of Technology,
Atlanta, GA 30332, USA.

On 4/26/06, Kenneth Piers <Pier@calvin.edu> wrote:
>
> Friends: Here are some of my perhaps uninformed musings. I am a
> self-acknowledged climate-change novice, although I tend to be much more
> impressed by the empirical evidence in support of the global warming
> hypothesis than some others contributing to this list. Although I tend to
> agree that one season of extraordinarily active and strong hurricanes does
> not prove global warming, I think all will agree that it does not invalidate
> it either; in fact such activity is more or less consistent with model
> predictions.
> I also think that the conclusion that a 0.5 deg C average global ocean
> surface warming is not sufficient to stimulate such storm activity may be
> suspect. Could it not be that ocean surface temperatures in the equatorial
> latitudes may be warming more than the global average? ( I don't know what
> the measurements show if there are any). And might not this be more severe
> in the region of the south Atlantic/Carribean? If the thermalhaline
> circulation, which carries warm water northward away from the equator, is
> actually slowing down, would not this result in increasing average surface
> temperatures at equatorial latitudes (and decreasing surface temperatures in
> the higher latitudes) just in the region where we are seeing increased storm
> action and intensity?
> I believe that one of the factors that plays a significant role in
> hurricane intensity is the amount of water vapor in the air. This, in turn,
> must be at least partially dependent on the vapor pressure of the ocean
> water underneath the storm center which in turn is dependent on the surface
> ocean temperature. It seems to me worth noting that in the temperature
> regime of summer surface ocean in the equatorial regions the vapor pressure
> of water increases at a rate of about 6% per deg C. So it would not take a
> large increase in the summer surface ocean temperature to cause a
> significant increase in surface water vapor pressure and therefore more
> water vapor in the atmosphere. And all this could add up to support greater
> storm frequency and intensity.
> I would very much like to learn more about this so if all of this is wrong
> please correct me.
> Respectfully,
> Ken Piers
>
>
> Ken Piers
>
> "We are by nature creatures of faith, as perhaps all creatures are; we
> live by counting on things that cannot be proved. As creatures of faith, we
> must choose either to be religious or superstitious, to believe in things
> that cannot be proved or to believe in things that can be disproved."
> Wendell Berry
>
> >>> "Rich Blinne" <rich.blinne@gmail.com> 4/26/2006 11:29 AM >>>
> Recently, I have given examples of why I believe global warming is real. I
> now want to give an example where I believe the case is oversold. The
> (less
> famous) :-) Dr. Gray from Colorado State cogently explains why global
> warming does not explain current hurricane intensities. There have been a
> flurry of papers that conclude the other way recently nevertheless Dr.
> Gray
> is holding his own. We shall see who prevails as the research continues.
>
> http://hurricane.atmos.colostate.edu/Forecasts/2005/dec2005/
>
>
> > There is no physical basis for assuming that global hurricane intensity
> or
> > frequency is necessarily related to global mean surface temperature
> changes
> > of less than ± 0.5oC. As the ocean surface warms, so too does global
> > upper air temperatures to maintain conditionally unstable lapse-rates
> and
> > global rainfall rates at their required values. Seasonal and monthly
> > variations of sea surface temperature (SST) within individual storm
> basins
> > show only very low correlations with monthly, seasonal, and yearly
> > variations of hurricane activity. Other factors such as tropospheric
> > vertical wind shear, surface pressure, low level vorticity, mid-level
> > moisture, etc. play more dominant roles in explaining hurricane
> variability
> > than do surface temperatures. Although there has been a general global
> > warming over the last 30 years and particularly over the last 10 years,
> the
> > SST increases in the individual tropical cyclone basins have been
> smaller
> > (about half) and, according to the observations, have not brought about
> any
> > significant increases in global major tropical cyclones except for the
> > Atlantic which as has been discussed, has multi-decadal oscillations
> driven
> > primarily by changes in Atlantic salinity. No credible observational
> > evidence is available or likely will be available in the next few
> decades
> > which will be able to directly associate global surface temperature
> change
> > to changes in global hurricane frequency and intensity.
> >
>
>
> Some comments from the peanut gallery. Note that Dr. Gray admits that
> global
> warming is real. He notes what I mentioned previously that global warming
> is
> far less pronounced in the tropics than the poles such that the
> SST increases in the tropical basins are half of the overall average. If
> there was more warming in the basins then it would be a more significant
> effect. For now, it's swamped by other factors. The other thing to note is
> the discussion of thermohaline circulation as the primary driver of
> hurricanes. Recall my previous post, ice cap melting makes this less
> pronounced. This means that global warming produces two countervailing
> effects on hurricanes. Just like global warming might produce a slightly
> cooler Europe because of a less pronounced Gulf Stream (this is nowhere
> near
> the "Day after Tomorrow" scenario), it is altogether possible that global
> warming may actually produced SMALLER HURRICANES! So much for the
> alarmists.
>
> Dr. Gray appears to be focusing on the effects of global warming and
> hurricanes and focusing less on the yearly forecast. I look forward to
> seeing his upcoming work.
>
Received on Thu Apr 27 08:24:45 2006