MORE GREENIE "MAYBES" ABOUT HURRICANES

There have been a few articles about a recent piece of scientific research which seems to show that hurricanes have become stronger if fewer in recent years. And so we get the inevitable link to global warming. But the further back you go towards the original research report, the more "maybes" you encounter. The article in The Times has a few ifs and buts about whether that villainous global warming might be the culprit but you get a lot more doubts when you look at the report from a science magazine that I reproduce below. Note also that climate scientist Roy Spencer seems to have been aware of the work concerned before it was published and commented as follows:

"There is some recent research that suggests that of all Atlantic and West Pacific tropical cyclones measured since the 1970's, a warming trend in sea surface temperatures has been accompanied by stronger and longer-lived storms. In fact, the increase in the total power generated by the storms that the study computed was actually much larger than could be accounted for by theory, suggesting changes in wind shear or other processes are operating in addition to just increased temperatures".

I have highlighted some of the maybes in red below. I have no doubt that the "more research is needed" conclusion will produce a juicy flow of research grants ($$$$$!) to the scientists concerned. I expect to have a couple more posts about the hurricane hullabaloo tomorrow.

"A study to be published tomorrow provides striking new evidence linking giant hurricanes such as Katrina-which devastated the Gulf of Mexico last month-to rising ocean temperatures, scientists say. That, the researchers added, provides new reason to study whether global warming is making hurricanes stronger, as some suspect. The evidence to date, while intriguing, doesn't prove the case, scientists said. This is partly because studies so far include only a few decades' worth of data, which isn't enough.

It's also because scientists lack a detailed explanation of how global warming would cause the hurricane trends seen so far. For instance, hurricanes are getting stronger, but not more frequent, and scientists don't know why. In general, it makes sense that higher temperatures would boost hurricane strength, many scientists say. Heat is energy, and energy drives hurricanes.

The study, to appear tomorrow in the research journal Science, is at least the second to link stronger hurricanes with rising temperatures. The link is statistical: as temperatures have risen, hurricanes have become more violent, the researchers said. Whether the first causes the second remains unproven. "What we found was rather astonishing," said Peter Webster of the Georgia Institute of Technology in Atlanta, Ga., lead author of the study. "In the 1970's, there was an average of about 10 Category 4 and 5 hurricanes per year globally. Since 1990, the number of Category 4 and 5 hurricanes has almost doubled, averaging 18 per year globally."

Category 4 hurricanes have sustained winds from 131 to 155 miles per hour; Category 5 systems, such as Hurricane Katrina at its peak over the Gulf of Mexico, feature winds of 156 mph or more. Katrina slammed its full force against the country blamed most widely for global warming-the United States. The warming is believed to be caused by increasing atmospheric levels of carbon dioxide a byproduct of human burning of fossil fuels such as coal and petroleum. The gases trap heat in the atmosphere. "Category 4 and 5 hurricanes made up about 20 percent of all hurricanes in the 1970's, but over the last decade they account for about 35 percent of these storms," said Georgia Tech's Judith Curry, a co-author of the study.

All this is happening as sea-surface temperatures are rising globally-from around one-half to one degree Fahrenheit, depending on the region, for hurricane seasons since the 1970s, the researchers said. "Our work is consistent with the concept that there is a relationship between increasing sea surface temperature and hurricane intensity," said Webster. "However, it's not a simple relationship. In fact, it's difficult to explain why the total number of hurricanes and their longevity has decreased during the last decade, when sea surface temperatures have risen the most."

The only region that is experiencing more hurricanes overall is the North Atlantic, where they have become more numerous and longer-lasting, especially since 1995, Webster said. The North Atlantic has averaged eight to nine hurricanes per year in the last decade, compared to the six to seven per year before the increase, the authors reported. Category 4 and 5 hurricanes in the North Atlantic have increased at an even faster clip: from 16 in the period of 1975-89 to 25 in the period of 1990-2004, a rise of 56 percent.

A study published in July in the journal Nature came to a similar conclusion. Focusing on North Atlantic and North Pacific hurricanes, Kerry Emanuel of the Massachusetts Institute of Technology in Cambridge, Mass. found an increase in their duration and power, although it used a different measurement to determine a storm's power.

To prove whether human-induced warming is cause the trend will require "a longer data record of hurricane statistics," Webster said. Also, "we need to understand more about the role hurricanes play in regulating the heat balance and circulation in the atmosphere and oceans." Computer simulations do show global warming would produce stronger hurricanes, researchers said. The new findings "will stimulate further research" into both natural and human-driven processes influencing hurricane trends, said Jay Fein, director of climate and large scale dynamics program at the National Science Foundation in Arlington, Va., which funded the research.

Webster is studying the role of hurricanes in climate. "The thing they do more than anything is cool the oceans by evaporating the water and then redistributing the oceans' tropical heat to higher latitudes," he said. "But we don't know a lot about how evaporation from the oceans' surface works when the winds get up to around 100 miles per hour, as they do in hurricanes." Understanding this is key to learning whether global warming is fueling hurricanes, he added. "If we can understand why the world sees about 85 named storms a year and not, for example, 200 or 25, then we might be able to say that what we're seeing is consistent with what we'd expect in a global warming scenario. Without this understanding, a forecast of the number and intensity of tropical storms in a future warmer world would be merely statistical extrapolation."







ARE THE OCEANS RUNNING LOW ON SALT?

Greenies are always panicing that the oceans are getting bigger inflows of fresh water (from melting glaciers or whatever) these days and that this could have all sorts of dire effects. Good news folks! It ain't gonna happen. There's also a lot of salty water pouring in and the best guess is that eveything is stable on the overall salt front. A plain (well, plainish) English summary of the latest article from here follows and then I reproduce the abstract from the original academic journal article.

"There has been much speculation about how global warming might affect the large-scale thermohaline circulation of the oceans. Freshwater inputs to the North Atlantic Ocean have been increasing, and reduced surface water salinities here might retard deep water formation and slow deep ocean circulation in general. However, measurements have also revealed that the water supplied to the Arctic Ocean and Nordic Seas by the Atlantic Inflow have been increasing in salinity. By combining observations and results from a numerical Ocean General Circulation Model, Hatun et al. (p. 1841) show that the salinity of Atlantic Inflow is closely related to the strength of the North Atlantic subpolar gyre, and that these recent salinity increases could help stabilize thermohaline circulation".


Influence of the Atlantic Subpolar Gyre on the Thermohaline Circulation

By: Hjalmar Hatun, Anne Britt Sando, Helge Drange, Bogi Hansen, Hethinn Valdimarsson

During the past decade, record-high salinities have been observed in the Atlantic Inflow to the Nordic Seas and the Arctic Ocean, which feeds the North Atlantic thermohaline circulation (THC). This may counteract the observed long-term increase in freshwater supply to the area and tend to stabilize the North Atlantic THC. Here we show that the salinity of the Atlantic Inflow is tightly linked to the dynamics of the North Atlantic subpolar gyre circulation. Therefore, when assessing the future of the North Atlantic THC, it is essential that the dynamics of the subpolar gyre and its influence on the salinity are taken into account.

(The Doi (permanent) address for the full article above is here but does not seem to be working yet so this link can be used)

***************************************

Many people would like to be kind to others so Leftists exploit that with their nonsense about equality. Most people want a clean, green environment so Greenies exploit that by inventing all sorts of far-fetched threats to the environment. But for both, the real motive is to promote themselves as wiser and better than everyone else, truth regardless.

Global warming has taken the place of Communism as an absurdity that "liberals" will defend to the death regardless of the evidence showing its folly. Evidence never has mattered to real Leftists

Comments? Email me here. My Home Page is here or here. For times when blogger.com is playing up, there are mirrors of this site here and here.

*****************************************