Sunday, December 30, 2012

Research Meteorologist Finds No Increase In Atlantic Hurricane Activity Despite Claims of Global Warming

This evening I stumbled across a review titled "Global Warming and Hurricanes: An Overview of Current Research Results."  The review, by Thomas R. Knutson,  a research meteorologist at the Geophysical Fluid Dynamics Laboratory, was written in 2008 and updated on November 28, 2012.  It sought to answer the question "Has Global Warming Affected Atlantic Hurricane Activity?"

According to its website, GFDL "works cooperatively with the [National Oceanic and Atmospheric Administration] to advance its expert assessments of changes in national and global climate through research, improved models, and products."

It is apparent from reading the report that Mr. Knutson is very supportive of the anthropogenic (man made) global warming theory.  He seemed very eager to prove that global warming had caused an increase in Atlantic hurricane activity.  In conducting his study, he used data to go beyond the typical 50 year historical record of Atlantic hurricanes.   To Mr. Knutson's credit, he reported the data honestly:
To gain more insight on this problem, we have attempted to analyze much longer (> 100 yr) records of Atlantic hurricane activity. If greenhouse warming causes a substantial increase in Atlantic hurricane activity, then the century scale increase in tropical Atlantic SSTs since the late 1800s should have produced a long-term rise in measures of Atlantic hurricanes activity.
Existing records of past Atlantic tropical storm numbers (1878 to present) in fact do show a pronounced upward trend, which is also correlated with rising SSTs.... However, the density of reporting ship traffic over the Atlantic was relatively sparse during the early decades of this record, such that if storms from the modern era (post 1965) had hypothetically occurred during those earlier decades, a substantial number would likely not have been directly observed by the ship-based "observing network of opportunity." We find that, after adjusting for such an estimated number of missing storms, there is a small nominally positive upward trend in tropical storm occurrence from 1878-2006. But statistical tests reveal that this trend is so small, relative to the variability in the series, that it is not significantly distinguishable from zero.... In addition, a new study by Landsea ... notes that the rising trend in Atlantic tropical storm counts is almost entirely due to increases in short-duration (less than 2 days) storms alone. Such short-lived storms were particularly likely to have been overlooked in the earlier parts of the record, as they would have had less opportunity for chance encounters with ship traffic. In short, the historical tropical storm count record does not provide compelling evidence for a substantial greenhouse warming induced long-term increase.
Thomas Knutson
If we instead consider Atlantic basin hurricanes, rather than all Atlantic tropical storms, the result is similar: the reported numbers of hurricanes were sufficiently high during the 1860s-1880s that again there is no significant positive trend in numbers beginning from that era (Figure 4, black curve, from CCSP 3.3 (2008) ). This is without any adjustment for "missing hurricanes".  (Emphasis is in the original document.)
The evidence for an upward trend is even weaker if we look at U.S. landfalling hurricanes, which even show a slight negative trend beginning from 1900 or from the late 1800s (Figure 4, blue curve)....
As a scientist Knutson had set out a hypothesis, i.e. that global warming had led to an increase in Atlantic hurricane activity, and found that, upon a fair assessment of the data, the hypothesis could not be proven. The report should have ended there. Instead Knutson changes the focus of his report to making predictions about the future of hurricanes incorporating into those predictions all kinds of scary projections about rising temperatures.  Knutson concludes:
climate warming will cause hurricanes in the coming century to be more intense globally and to have higher rainfall rates than present-day hurricanes. In my view, there are better than even odds that the numbers of very intense (category 4 and 5) hurricanes will increase by a substantial fraction in some basins, while it is likely that the annual number of tropical storms globally will either decrease or remain essentially unchanged.
So in a nutshell, Knutson set out to prove that global warming had resulted in increased hurricane activity.  Failing to find data to support that, Knutson switches to making guesses about the future of hurricanes based on "model simulations of greenhouse warming."

More evidence of politicization of his role of a scientist is evident from his Knutson's conclusions which actually leads off the report:
  • It is premature to conclude that human activities--and particularly greenhouse gas emissions that cause global warming--have already had a detectable impact on Atlantic hurricane activity. That said, human activities may have already caused changes that are not yet detectable due to the small magnitude of the changes or observational limitations, or are not yet properly modeled (e.g., aerosol effects).
  • Anthropogenic warming by the end of the 21st century will likely cause hurricanes globally to be more intense on average (by 2 to 11% according to model projections for an IPCC A1B scenario). This change would imply an even larger percentage increase in the destructive potential per storm, assuming no reduction in storm size.
  • There are better than even odds that anthropogenic warming over the next century will lead to an increase in the numbers of very intense hurricanes in some basins—an increase that would be substantially larger in percentage terms than the 2-11% increase in the average storm intensity. This increase in intense storm numbers is projected despite a likely decrease (or little change) in the global numbers of all tropical storms. 
  • Anthropogenic warming by the end of the 21st century will likely cause hurricanes to have substantially higher rainfall rates than present-day hurricanes, with a model-projected increase of about 20% for rainfall rates averaged within about 100 km of the storm center. 
Knutson devotes only one paragraph, the first one, to the conclusion he reached after studying the hurricane data.  In the paragraph though h all but apologizes for concluding the data do not show a correlation between global warming and increased hurricane activity and even suggests the reader disregard that conclusion.  He then proceeds to spend three paragraphs talking about predictions about future hurricane activity based on computer models of increased global warming, which was not at all the express purpose of his report.

It is important to note that these conclusions, inserted at the beginning of his report, would be the only thing that many media outlets, politicians and other lay people would read.  The headlines would be that Mr. Knutson researched the issue and found that global warming increased hurricane activity when in fact his review of the data proved just the opposite.

As I have said before, the politicization of our science is one of the most dangerous trends today.


StillWind said...

Good analysis of the article. How they're still selling AGW Theory is beyond amy rational explanation. Howver, they have gone beyond scinece and created a new religion, and like all religions, it is based on faith, and not data.
This is not new to science, btw. Science has always been ruled by politics, both in academia and the ruling class.
The difference now is that the average person can also access the data and call these guys out.

varangianguard said...

That isn't necessarily "politicization". You are looking at this through you rown skewed lens (nice to miss that part).
Lots of reserach is self-validating in nature. One wants to "prove" that one is more correct than the next "competitor" for scarce research monies. More correct = better funded.

Really Paul. You are the one politicizing this discussion.

Indy Rob said...

The issue that Paul points out is that this researcher found no data that validated the AGW theory and the results of this warming; that due to increased global temperature, that hurricanes would intensify and be more common.
And even though the researcher found nothing measurable that would support the AGW theory, he still started his research paper by insisting that theory was fact, and that his negative results were caused by something other than the theory being wrong.

varangianguard said...

Par for the course in science. Nothing new here to see. Move along.

If you find this kind of research processing distasteful, then help push for more realism in the process. This is a side effect of the quantification of everything academic. Has been coming since quantitative research began pushing qualitative research to the sidelines.

"Statistics. The science of never having to say you were wrong."

RhondaLeeBaby69 said...

You're the one politicizing the discussion, PO. The report does nothing to discredit global warming. It merely shows that global warming has not significantly increased hurricane activity in the Atlantic ocean.

RhondaLeeBaby69 said...

You're the one politicizing the discussion, PO. The report does nothing to discredit global warming. It merely shows that global warming has not significantly increased hurricane activity in the Atlantic ocean.

This is not a case of "if global warming were fact, then hurricane activity should have increased". It is more, "global warming is a fact, however, it has not led to increased Atlantic hurricane activity".

Paul K. Ogden said...
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Paul K. Ogden said...
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Paul K. Ogden said...

Indy Rob's analysis is spot on. The scientist should be presenting his research conclusions and doing nothing more. Instead, when he found out the data didn't support the anthropenicglobal warming theory, he apologized for his conclusions and tried to prove other explanations for the data not being what he thought it would be. Then he went off into discussing computer modeling showing that, in the future, global warming would affect hurricane activity. Then, to top things off, he wrote a summary of his findings, barely mentioning the conclusions of his research based on actual data, which again was what he set out to study.

People who are in the field of science and/or academia need to study the issues and present conclusions without having a political agenda. The fact is our science has gotten away from that. Not too long ago we had Climategate, a discovery of emails between members of the science community in which they discussed how to present data in such a way to support the global warming, er climate change, agenda, while downplaying or suppressing data that didn't support the conclusion they wanted.

I won't even get into the hockey stick graph which even global warming advocates now admit was as phony as a $3 bil.

Scientists should NEVER be using the phrase "the debate is over" or talking about "scientific consensus." Scientists should ALWAYS welcome intellecutal challenge and debate about their conclusions. That's not the case anymore. And it's not just global warming. In happens on issues across the board. If your conclusions are not politically correct, you don't get grants, you don't get published and you're often ostracized by your peers.