Wednesday, December 29, 1999
Reuters
By James Poole
As tropical Thailand and Vietnam shivered in chilly temperatures over the past few days, experts ask whether this is another worrying sign of an ever more volatile world climate.
"Our climate is changing rapidly ... our new data and understanding point to a critical situation," said top officials from the U.S. National Oceanic and Atmospheric Administration (NOAA) and the British Meteorological Office in a recent letter to a London newspaper.
The last months of 1999 have witnessed a string of weather-related disasters — up to 50,000 people killed by mudslides and flash floods in Venezuela, 10,000 dead after a cyclone in eastern India, hundreds dead in Vietnam flooding, and more than 100 killed by storms and avalanches in Western Europe.
This followed 1998, a year already labeled by experts as the costliest ever for insured losses from catastrophes triggered by storms, floods, drought and fires.
U.S. temperatures in 1999 will be the second-warmest this century, topped only by 1998, NOAA said this week.
"As the average temperature goes up, we can expect more extreme events — floods, drought, more severe storms," according to British Meteorological Office head Peter Ewins.
El Niño , La Niña
Scientists say global warming is not the cause of a familiar weather pattern in Southeast Asia of a drought-inducing, hot El Niño followed by a rain-soaked, cool La Niña . But it may mean they happen more frequently.
The cycle — driven by the warming and cooling of the Pacific Ocean — is now in a strong La Niña phase and U.S. weather experts say it will continue at least into March.
La Niña has made the wet season in parts of Southeast Asia wetter than normal and temperatures have been cool.
Weather experts attribute the latest cold spell to a strong polar air mass that moved swiftly into Southeast Asia in recent days from Mongolia and China.
Cambodia temperatures lowest in 65 years
The cold air caused temperatures in Phnom Penh, the capital of tropical Cambodia, to fall to 16 degrees Celsius (61 degrees Fahrenheit) last week, the lowest in 65 years.
In Thailand at least 33 people have died from cold-related causes. At the country's coldest point at Loei in the northeast, the mercury dived to 2.9 degrees Celsius (37.2 degrees Fahrenheit) at one stage.
Australia weather officials said La Niña could also be the cause of cold weather in the southern hemisphere's summer. Heavy rain has kept holiday-makers away from Sydney beaches and threatens to douse New Year's Eve fireworks parties.
And Vietnam was hit by temperatures as low as six degrees Celsius (42.8 degrees Fahrenheit), affecting coffee harvesting and the drying of beans.
The cool temperatures will have slowed growth of tropical agricultural crops but they are not likely to have caused any significant damage, experts say. Though floods have hurt output in places, abundant rains will help crops resume growth as the temperatures rise.
Farmers are much more fearful of drought, such as that which devastated Southeast Asian oil palm, coffee, rubber and rice plantations in 1997. But for the time being at least, there is no sign of a resurgence of a scorching El Niño on the horizon.