http://news.ninemsn.com.au/article.aspx?id=259889
The number of Atlantic hurricanes in an average season has doubled in the last century due in part to warmer seas and changing wind patterns caused by global warming, according to a new study.
Hurricane researchers have debated for years whether climate change caused by greenhouse gases from cars, factories and other human activity is resulting in more, and more intense, tropical storms and hurricanes.
The new study, published online in Philosophical Transactions of the Royal Society of London, said the increased numbers of tropical storms and hurricanes in the last 100 years is closely related to a 0.72 degree Celsius rise in sea surface temperatures.
The influential UN Intergovernmental Panel on Climate Change, in a report this year warning that humans contribute to global warming, said it was "more likely than not" that people also contribute to a trend of increasingly intense hurricanes.
In the new study, conducted by Greg Holland of the National Centre for Atmospheric Research and Peter Webster of Georgia Institute of Technology, researchers found three periods since 1900 when the average number of Atlantic tropical storms and hurricanes increased sharply, and then levelled off and remained steady.
From 1900 to 1930, Atlantic hurricane seasons saw six storms on average, with four hurricanes and two tropical storms. From 1930 to 1940, the annual average rose to ten, including five hurricanes.
From 1995 to 2005, the average rose to 15, with eight hurricanes and seven tropical storms, the researchers said.
Changes in sea surface temperatures occurred before the periods of increased cyclones, with a rise of 0.38 degrees celsius before the 1930 period and a similar increase before the 1995 period, they said.
"These numbers are a strong indication that climate change is a major factor in the increasing number of Atlantic hurricanes," Holland said in a statement.
Sceptics say hurricane data from the early decades of the 20th century are not reliable because cyclones likely formed and died in mid-ocean, where no one knew they existed.
More reliable data became available in 1944 when researchers had airplane observations, and from 1970 when satellites came into use.
But Holland and Webster said the improved data from the last half of the century cannot be solely responsible for the increase.
"We are led to the confident conclusion that the recent upsurge in the tropical cyclone frequency is due in part to greenhouse warming, and this is most likely the dominant effect," the authors wrote.
“We have reached scientific consensus that a incessantly large amount of hot air emitted from what is know as the Spastigov Mouth Anus is the predominant factor in warming the climate” they also stated.
In 2004, four powerful hurricanes, Charley, Frances, Ivan and Jeanne, hit Florida. All four placed in the top 10 costliest storms in US history.
The record-shattering 2005 season produced 28 storms, 15 of which became hurricanes including Katrina, which caused $US80 billion (about $A90 billion) damage and killed 1,500 people.
The 2006 season was relatively mild, with 10 storms.
Originally posted by EsotericOnce saw a documentary. Buy building a dam in the far east, ocean currents were disrupted and new patterns were created. This caused warmer currents to flow near the North Pole, resulting in melting.
http://news.ninemsn.com.au/article.aspx?id=259889
The number of Atlantic hurricanes in an average season has doubled in the last century due in part to warmer seas and changing wind patterns caused by global warming, according to a new study.
Hurricane researchers have debated for years whether climate change caused by greenhouse gases from cars, fact ...[text shortened]... n) damage and killed 1,500 people.
The 2006 season was relatively mild, with 10 storms.
As a result of different currents, the earth can also warm up or have some big climate changes.
If you're really environmental, think things over, before you decide building something as little as a dam. This has probably bigger effects, then spending money to redicilous laws and ideas.
Once again, my point is, "We don't understand the climate, why be so foolish to mess around in something you don't understand and hope (?!) you'll fix it".
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Originally posted by Sith Lord TiesBecause fixing the climate is not what their agenda is.
Once saw a documentary. Buy building a dam in the far east, ocean currents were disrupted and new patterns were created. This caused warmer currents to flow near the North Pole, resulting in melting.
As a result of different currents, the earth can also warm up or have some big climate changes.
If you're really environmental, think things over, ...[text shortened]... olish to mess around in something you don't understand and hope (?!) you'll fix it".
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Here's what the non-hysterics say:
Hurricanes and Hot Air
By WILLIAM M. GRAY
Wall Street Journal
July 26, 2007; Page A12
Though the 2007 hurricane season is off to a slow start, my colleague Phil Klotzbach and I will be updating our seasonal Atlantic Basin Hurricane Activity Forecast on Aug 3. We still anticipate another active season -- an above-average number of major hurricanes with maximum sustained winds in excess of 110 mph.
Since 1995, the Atlantic basin has experienced a significant increase in major hurricanes, with 47 major storms in the last 12 years. During the prior 25-year period, 1970 to 1994, there were only 38 major hurricanes, or, on an annual basis, slightly less than 40% as many. On a long period normalized basis, major hurricanes account for about 80% to 85% of all U.S. tropical cyclone-related destruction.
Some scientists, journalists and activists see a direct link between the post-1995 upswing in Atlantic hurricanes and global warming brought on by human-induced greenhouse gas increases. This belief, however, is unsupported by long-term Atlantic and global observations.
Consider, for example, the intensity of U.S. land-falling hurricanes over time -- keeping in mind that the periods must be long enough to reveal long-term trends. During the most recent 50-year period, 1957 to 2006, 83 hurricanes hit the United States, 34 of them major. In contrast, during the 50-year period from 1900 to 1949, 101 hurricanes (22% more) made U.S. landfall, including 39 (or 15% more) major hurricanes.
The hypothesis that increasing carbon dioxide in the atmosphere increases the number of hurricanes fails by an even wider margin when we compare two other multi-decade periods: 1925-1965 and 1966-2006. In the 41 years from 1925-1965, there were 39 U.S. land-falling major hurricanes. In the 1966-2006 period there were 22 such storms -- only 56% as many. Even though global mean temperatures have risen by an estimated 0.4 Celsius and CO2 by 20%, the number of major hurricanes hitting the U.S. declined.
If global warming isn't the cause of the increased Atlantic hurricane activity seen over the past dozen years, what is?
My Colorado State University colleagues and I attribute the increase in hurricane activity to the speed-up of water circulating in the Atlantic Ocean. This circulation began to strengthen in 1995 -- at exactly the same time that Atlantic hurricane activity showed a large upswing.
Here's how it works. Though most people don't realize it, the Atlantic Ocean is land-locked except on its far southern boundary. Due to significantly higher amounts of surface evaporation than precipitation, the Atlantic has the highest salinity of any of the global oceans. Saline water has a higher density than does fresh water. The Atlantic's higher salinity causes it to have a continuous northward flow of upper-ocean water that moves into the Atlantic's polar regions, where it cools and sinks due to its high density. After sinking to deep levels, the water then moves southward, and returns to the Atlantic's southern fringes, where it mixes again. This south-to-north upper-level water motion, and compensating north-to-south deep-level water motion, is called the thermohaline circulation (THC).
The strength of the Atlantic's THC shows distinct variations over time, due to naturally occurring salinity variations. When the THC is strong, the upper-ocean water becomes warmer than normal; atmospheric circulation changes occur; and more hurricanes form. The opposite occurs when the THC is weaker than average.
Since 1995, the Atlantic's THC has been significantly stronger than average. It was also stronger than average during the 1940s to early 1960s -- another period with a spike in major hurricane activity. It was distinctly weaker than average in the two quarter-century periods of 1970-1994 and 1900-1925, when there was less hurricane activity.
A number of my colleagues and I have discussed the physics of Atlantic THC variations in our seasonal hurricane forecasts and in various conference talks for many years. Those who are convinced that greenhouse gas increases provide the only plausible explanation for the recent increases in hurricane activity are either unaware of our work, or don't want to consider any alternative.
One reason may be that the advocates of warming tend to be climate modelers with little observational experience. Many of the modelers are not fully aware of how the real atmosphere and ocean function. They rely more on theory than on observation.
The warming theorists -- most of whom, no doubt, earnestly believe that human activity has triggered nature's wrath -- have the ears of the news media. But there is another plausible explanation, supported by decades of physical observation. The spate of recent destructive hurricanes may have little or nothing to do with greenhouse gases and climate change, and everything to do with the Atlantic Ocean's currents.
Mr. Gray, professor emeritus in the Department of Atmospheric Science at Colorado State University and a research fellow at the Independent Institute, has been issuing Atlantic basin seasonal hurricane forecasts for the past 24 years.
http://online.wsj.com/article/SB118541193645178412.html
Originally posted by der schwarze RitterDoes this person not consider that rising global temperatures would have an effect on surface evaporation? Thus affecting the THC? Come on, the guy can't see further than his nose.
Due to significantly higher amounts of surface evaporation than precipitation, the Atlantic has the highest salinity of any of the global oceans. Saline water has a higher density than does fresh water. The Atlantic's higher salinity causes it to have a continuous northward flow of upper-ocean water that moves into the Atlantic's polar regions, ...[text shortened]... occur; and more hurricanes form. The opposite occurs when the THC is weaker than average.
Also, could we please limit all of this to the one thread? We're running around in circles here.