Even in the research files of the Commonwealth Scientific and Industrial Research Organization's (CSIRO) Climate Change Risk and Impact Division in Melbourne, there are images of a lost city of immense beauty captured before the giant storm of Sept. 8, 1900 that turned it into piles of corpses and smashed timber.
Galveston never reclaimed is early glory, with nearby Houston taking over its role as a center of commerce and culture. Its streets were littered with between 6,000 and 8,000 dead, its ornate and fanciful 19th century architecture broken apart and blown into the Gulf of Mexico to become flotsam. Also in the archives are records of Cyclone Mahina, of March 1899 that killed 400 people in Bathurst Bay, Queensland, three quarters of them aboard pearling luggers, and another 100 Aboriginal people living on the mainland. It was the deadliest and most violent storm ever recorded in Australia, generating 10m high waves and 300kph winds, and outstripping the better known Cyclone Tracy disaster of Christmas Eve, 1974, which destroyed the northern port city of Darwin and killed 65 people.
Hurricanes -- or cyclones or typhoons as they are variously known -- start as low pressure cells that suck up the latent heat energy of dense moist air lying over areas of sea surface temperature of at least 26oC. But because many of the oceanic storm generating areas now have unprecedentedly high surface temperatures, in the case of the Gulf of Mexico, over 30oC, the principal researcher at the division, Penny Whetton, has spent a week fielding media questions as to whether Katrina was caused by global warming.
"The short answer is we can't prove a link," Whetton says. But she can explain why a link may well be established in the future. "The data or signals from tropical storms is very hard to decipher," she says.
"We have learned that they are at their most frequent north of the equator they are generally least active south of the equator, and vice versa."
"They also vary in frequency and intensity over very long cycles, of around 20-50 years depending on how you define them." Whetton says there are four tests of climate change being a factor in violent tropical storms.
"They are: whether these storms are more intense, whether there is a change in their frequency, whether they are beginning to track further north or south of the equator, and whether they are starting to appear in new locations within the narrow latitudinal bands they generally occupy -- roughly 20 degrees north to 20 degrees south yet remaining clear of the actual equator," she says. She says there is no clear signal of a change in frequency of hurricanes, either in terms of occurring more or less frequently, after taking into account normal cyclical variations. There is no evidence of cyclones or hurricanes tracking further north or south into higher latitudes.
Subscribe
Subscribe to IEMA's newsletters to receive timely articles, expert opinions, event announcements, and much more, directly in your inbox.
Posted on 13th September 2005
Latest Posts
-
Labour's plan for economic growth must mean green growth – but there is a green skills gap looming
- 5th July 2024 -
As Labour plans to “slash red tape” for economic growth, YouGov poll finds 3 in 5 people want to increase public involvement in planning system
- 28th June 2024 -
Medtronic agrees partnership with IEMA to accelerate skills and standards in sustainability
- 21st June 2024 -
Landmark climate impact ruling for fossil fuel projects, cites IEMA guidance
- 20th June 2024 -
IEMA sets out 18 policy asks for the next Government
- 3rd June 2024 -
New global alliance formed for 25,000 environment and sustainability professionals
- 29th May 2024