Tropical storms have doubled in destructive potential in the past 30 years because ocean surfaces have become warmer, according to a leading climate researcher.
This is the first time that an increase in the size, duration and power of tropical storms has been linked to global warming.
The result could have a significant effect on British weather, and have potentially disastrous consequences for the Caribbean, the west coast of the US and Pacific countries such as Japan.
Kerry Emanuel, of the atmospheric, oceans and climate research department at the Massachusetts Institute of Technology, has studied data from all the severe storms -- or tropical cyclones -- over the past 30 years.
He says they have been more intense and longer in duration, and have generated far more power, than computer models had predicted.
Thermodynamics
Emanuel, an acknowledged world expert on the thermodynamics of tropical cyclone research, told the Guardian that he believed the power of the storms to create huge waves and mix the surface water of the oceans could also effect ocean currents -- ?particularly the Gulf Stream, which sends warm water northwards and keeps Britain's climate milder than it otherwise would be.
Many scientists have predicted that the Gulf Stream could slow or be "turned off" by the effect of increased fresh water entering the Arctic from melting ice.
Greater mixing
But Emanuel believes that the greater mixing of warm water in the tropics could have the opposite effect -- speeding up the currents and driving more warm water north.
Although there is no connection between his research and recent observations in Iceland, temperatures in the North Atlantic have risen notably as as a direct result of a strong current flow pushing farther north.
Emanuel's findings, published in Nature magazine, follow an inconclusive scientific debate about whether the frequency of storms is a natural phenomenon or a result of man-made climate change.
Climate models
Climate models run through computers indicate that storms are likely to become more severe, but this is the first evidence that this phenomenon is already happening.
What is surprising is that the severity is far more pronounced than the computer models have predicted.
According to the paper, the computer models estimated that wind speeds would increase by 2 to 3 percent as a result of an already observed rise in the ocean temperature of 5?C.
Total force
Because of the longer duration of storms, this would increase the total force exerted by the average hurricane by 8 to 12 percent.
However, Emanuel's measurements of real winds show that storms can pick up much greater intensity as the ocean waters mix.
During a storm, the winds cause the warm surface water to mix with the cooler ocean below.
Normally, this mixing would puts a brake on the power of the storm because of the overall reduction in sea temperature caused by the mixing.
But measurements show that it is not just the surface of the sea that has warmed in recent decades -- the layer underneath is also at a higher temperature.
This means that the wave action that mixes the layers does not have such a pronounced cooling effect as before and, as a result, the intensity of the storm remains significantly higher.
Emanuel's view is that at least part of this increase in ocean temperature is caused by man-made climate change.
"Whatever the cause, the near doubling of power dissipation over the period of record should be a matter of some concern, as it is a measure of the destructive potential of tropical cyclones," Emanuel said.
Julian Heming, a tropical prediction scientist with the Met Office in Exeter, said that he did not question Emanuel's measurements.
But Heming pointed out that there was disagreement among scientists about whether the observed trend was man-made or part of a natural cycle.
POLITICAL PRISONERS VS DEPORTEES: Venezuela’s prosecutor’s office slammed the call by El Salvador’s leader, accusing him of crimes against humanity Salvadoran President Nayib Bukele on Sunday proposed carrying out a prisoner swap with Venezuela, suggesting he would exchange Venezuelan deportees from the US his government has kept imprisoned for what he called “political prisoners” in Venezuela. In a post on X, directed at Venezuelan President Nicolas Maduro, Bukele listed off a number of family members of high-level opposition figures in Venezuela, journalists and activists detained during the South American government’s electoral crackdown last year. “The only reason they are imprisoned is for having opposed you and your electoral fraud,” he wrote to Maduro. “However, I want to propose a humanitarian agreement that
ECONOMIC WORRIES: The ruling PAP faces voters amid concerns that the city-state faces the possibility of a recession and job losses amid Washington’s tariffs Singapore yesterday finalized contestants for its general election on Saturday next week, with the ruling People’s Action Party (PAP) fielding 32 new candidates in the biggest refresh of the party that has ruled the city-state since independence in 1965. The move follows a pledge by Singaporean Prime Minister Lawrence Wong (黃循財), who took office last year and assumed the PAP leadership, to “bring in new blood, new ideas and new energy” to steer the country of 6 million people. His latest shake-up beats that of predecessors Lee Hsien Loong (李顯龍) and Goh Chok Tong (吳作棟), who replaced 24 and 11 politicians respectively
Young women standing idly around a park in Tokyo’s west suggest that a giant statue of Godzilla is not the only attraction for a record number of foreign tourists. Their faces lit by the cold glow of their phones, the women lining Okubo Park are evidence that sex tourism has developed as a dark flipside to the bustling Kabukicho nightlife district. Increasing numbers of foreign men are flocking to the area after seeing videos on social media. One of the women said that the area near Kabukicho, where Godzilla rumbles and belches smoke atop a cinema, has become a “real
‘WATER WARFARE’: A Pakistani official called India’s suspension of a 65-year-old treaty on the sharing of waters from the Indus River ‘a cowardly, illegal move’ Pakistan yesterday canceled visas for Indian nationals, closed its airspace for all Indian-owned or operated airlines, and suspended all trade with India, including to and from any third country. The retaliatory measures follow India’s decision to suspend visas for Pakistani nationals in the aftermath of a deadly attack by shooters in Kashmir that killed 26 people, mostly tourists. The rare attack on civilians shocked and outraged India and prompted calls for action against their country’s archenemy, Pakistan. New Delhi did not publicly produce evidence connecting the attack to its neighbor, but said it had “cross-border” links to Pakistan. Pakistan denied any connection to
RSS