The beginning of the end, or storm in a teacup?
October 2, 2004
Faster ocean currents - not global warming - could be behind the storms, floods and fires, writes Melissa Fyfe.
A record-breaking spate of hurricanes hitting Florida, a string of deadly typhoons in Japan, Arctic ice melting, Antarctic glaciers moving, heatwaves, floods - the world has, it seems, gone mad.
When nature unleashes her temper, we want to know why. But the answer, as always, is not clear-cut. The planet moves in mysterious ways.
Blaming global warming for polar ice melting is one thing, but the world's climate scientists will not connect it to the recent hurricanes that whipped the Caribbean with unprecedented frequency.
There are simply too many forces at play and not enough long-term data, they say.
But a key factor, scientists believe, was the build-up of warm water in the Atlantic in the past year, about five degrees higher than recent averages.
US meteorologists have said the ocean conveyor belt that ferries warm water around the globe is probably to blame for the spate of hurricanes.
Scientists have discovered that every two or three decades this massive ocean current picks up speed, warming water in the tropics. This in turn changes atmospheric conditions around Africa, where many major storms begin.
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Climatologist Stephen Schneider, of Stanford University, said five factors controlled the magnitude and frequency of tropical cyclones. They included the thickness of the atmosphere, how strong winds were at the top of a storm and the temperature of the upper 200 metres of the ocean.
"We have no idea how global warming is going to affect four out of five of these factors, but we are sure it is going to increase ocean temperatures," he said.
"The warmer the water, the more the energy."
In the future, this could be true of tropical cyclones in Australia's north, Professor Schneider said. "Maybe you won't have stronger storms every year, but when you do get a doozy, it is going to be a big one."
This year has been one of extreme weather, and scientists - particularly climate scientists, atmospheric chemists and oceanographers - are warning that the kind of extreme weather that happened once in 100 years could soon take place every 20 years.
Last month, British scientist Mike Pilling, a professor of physical chemistry at Leeds University, said millions of people could die due to extreme weather events caused by climate change.
Professor Pilling cited the European heatwave and increased atmospheric pollution that killed 35,000 in Europe in 2003. Scientists have found global warming has also pushed up temperatures at night, providing no relief during heatwaves.
Last year, the Red Cross estimated that up to 700 natural disasters took 50,000 lives, almost five times as many as 2002. In 2003, the United Nations reported that climate-related impacts cost the world $US602 billion ($A83 billion) 10 per cent more than in 2002.
The insurance business is one of the most vocal supporters for action on climate change. Australia's biggest insurance group, IAG, has done the figures on the cost of climate-related disasters - such as the Sydney hailstorm of 1999 that caused
The beginning of the end, or storm in a teacup?
October 2, 2004
Faster ocean currents - not global warming - could be behind the storms, floods and fires, writes Melissa Fyfe.
A record-breaking spate of hurricanes hitting Florida, a string of deadly typhoons in Japan, Arctic ice melting, Antarctic glaciers moving, heatwaves, floods - the world has, it seems, gone mad.
When nature unleashes her temper, we want to know why. But the answer, as always, is not clear-cut. The planet moves in mysterious ways.
Blaming global warming for polar ice melting is one thing, but the world's climate scientists will not connect it to the recent hurricanes that whipped the Caribbean with unprecedented frequency.
There are simply too many forces at play and not enough long-term data, they say.
But a key factor, scientists believe, was the build-up of warm water in the Atlantic in the past year, about five degrees higher than recent averages.
US meteorologists have said the ocean conveyor belt that ferries warm water around the globe is probably to blame for the spate of hurricanes.
Scientists have discovered that every two or three decades this massive ocean current picks up speed, warming water in the tropics. This in turn changes atmospheric conditions around Africa, where many major storms begin.
Advertisement Advertisement
Climatologist Stephen Schneider, of Stanford University, said five factors controlled the magnitude and frequency of tropical cyclones. They included the thickness of the atmosphere, how strong winds were at the top of a storm and the temperature of the upper 200 metres of the ocean.
"We have no idea how global warming is going to affect four out of five of these factors, but we are sure it is going to increase ocean temperatures," he said.
"The warmer the water, the more the energy."
In the future, this could be true of tropical cyclones in Australia's north, Professor Schneider said. "Maybe you won't have stronger storms every year, but when you do get a doozy, it is going to be a big one."
This year has been one of extreme weather, and scientists - particularly climate scientists, atmospheric chemists and oceanographers - are warning that the kind of extreme weather that happened once in 100 years could soon take place every 20 years.
Last month, British scientist Mike Pilling, a professor of physical chemistry at Leeds University, said millions of people could die due to extreme weather events caused by climate change.
Professor Pilling cited the European heatwave and increased atmospheric pollution that killed 35,000 in Europe in 2003. Scientists have found global warming has also pushed up temperatures at night, providing no relief during heatwaves.
Last year, the Red Cross estimated that up to 700 natural disasters took 50,000 lives, almost five times as many as 2002. In 2003, the United Nations reported that climate-related impacts cost the world $US602 billion ($A83 billion) 10 per cent more than in 2002.
The insurance business is one of the most vocal supporters for action on climate change. Australia's biggest insurance group, IAG, has done the figures on the cost of climate-related disasters - such as the Sydney hailstorm of 1999 that caused $1.7 billion damage in minutes - and is calling for action.
Its modelling suggests that small changes to ocean temperature could create a "megastorm" that would dwarf the Sydney hailstorm.
"Global warming leads to increased severe weather-related events," IAG's chief actuary, Tony Coleman, said. "It manifests itself with more damage to buildings and cars, which leads to more claims, which is why the insurance industry is concerned."
While conditions here might not be as spectacular as hurricanes and typhoons, Australia is still experiencing some of its own severe weather. Severe rainfall deficiencies still persist on Australia's east coast from Proserpine in Queensland to Bega in southern NSW. And it's been unusually warm: last month NSW experienced record high temperatures for September.
Neil Plummer, acting superintendent of the Bureau of Meteorology's National Climate Centre, said there have been trends towards an El Nino event for the past few months, but it is too early to call. Nevertheless, it looks like the next three months will be warmer and drier than average in parts of eastern Australia.
THE WEATHER WITH YOU
· So far this year four hurricanes have hit Florida, the most since records began in 1851. The storms have caused damage worth an estimated $US12.2 billion ($A17 billion) including the house below, destroyed by hurricane Charley.
· This week's typhoon Meari left 20 people dead in Japan. Meari was the season's 21st typhoon in the Pacific and a record eighth to hit Japan.
· Antarctica's glaciers are accelerating their march towards the sea. A 3200-square-kilometre section of the Larson B iceshelf broke off over a month in 2002. The collapse was captured in these satellite images, right.
· Australia is still experiencing "severe rainfall deficiencies" on the east coast.
· 2004 has seen major fires in France, California and Greece and severe floods in Bangladesh, Nepal and India.
.7 billion damage in minutes - and is calling for action.
Its modelling suggests that small changes to ocean temperature could create a "megastorm" that would dwarf the Sydney hailstorm.
"Global warming leads to increased severe weather-related events," IAG's chief actuary, Tony Coleman, said. "It manifests itself with more damage to buildings and cars, which leads to more claims, which is why the insurance industry is concerned."
While conditions here might not be as spectacular as hurricanes and typhoons, Australia is still experiencing some of its own severe weather. Severe rainfall deficiencies still persist on Australia's east coast from Proserpine in Queensland to Bega in southern NSW. And it's been unusually warm: last month NSW experienced record high temperatures for September.
Neil Plummer, acting superintendent of the Bureau of Meteorology's National Climate Centre, said there have been trends towards an El Nino event for the past few months, but it is too early to call. Nevertheless, it looks like the next three months will be warmer and drier than average in parts of eastern Australia.
THE WEATHER WITH YOU
· So far this year four hurricanes have hit Florida, the most since records began in 1851. The storms have caused damage worth an estimated $US12.2 billion ($A17 billion) including the house below, destroyed by hurricane Charley.
· This week's typhoon Meari left 20 people dead in Japan. Meari was the season's 21st typhoon in the Pacific and a record eighth to hit Japan.
· Antarctica's glaciers are accelerating their march towards the sea. A 3200-square-kilometre section of the Larson B iceshelf broke off over a month in 2002. The collapse was captured in these satellite images, right.
· Australia is still experiencing "severe rainfall deficiencies" on the east coast.
· 2004 has seen major fires in France, California and Greece and severe floods in Bangladesh, Nepal and India.
