Warming up for another El Nino?

Could it happen again? The Petronas Towers in Kuala Lumpur (top) under a haze from Indonesia's fires and Sydney's Opera House (bottom) cloaked in bushfire smog.

HONG KONG, China -- It maybe too early to tell whether warming over the tropical Pacific Ocean is one of the tell tale signs that El Nino is back, yet talk about the return of this weather phenomena is already mounting.

While Australians declared an end to the fiercest bushfires in eight years and Indonesians and Kiwis mop up after torrential rain, those in the Asia-Pacific regioncould again be looking into the face of devastating weather to rival that of 1997.

Vernon Kousky, a climate specialist at NOAA, the National Oceanic and Atmospheric Administration, has said warming oceans and increasing cloud cover may be the first sign that El Nino is back and could affect the world's weather by mid-year.

Although Kousky stopped short of declaring a 2002 El Nino a certainty, this is the first time since the 1997-98 episode that the tropical Pacific has experienced a warming of this nature.

Warming episode

Next to the seasons, El Nino is one of the most powerful forces driving global weather and is the name for a weather condition marked by rising ocean temperatures in the tropical Pacific Ocean linked to warm air temperatures, increased rainfall, flooding, drought and wildfires.

If El Nino returns, it would hit the Asia-Pacific first and foremost with drier conditions in the sub-tropical Pacific and wetter weather further east and north.

In 1997-98 the fires in Indonesia raged throughout the 9-11 month dry period, devastating large tracts of tropical bush.

If it did strike back, El Nino could bring relief from the torrential rains now affecting Indonesia and New Zealand but for the already scorched areas of Australia it could bring further bush fires.

This time meteorologists have been quick to point out that historically there have been both mild and severe El Nino phenomena and that another two or three months are needed to confirm the situation.

However, some weather forecasters have been surprised by the early El Nino prediction.

"This is unusual. El Nino developments don't usually show this early in the year," Steven Mauget, a meteorologist for the U.S. Agriculture Department told Reuters News agency

"Usually the earlier they develop, the stronger they tend to be," he reiterated.

Tony Barnston, a weather expert with Columbia University, also told Reuters that there was a 60 to 70 percent chance of El Nino occurring by late spring.

Barnston believes this year's El Nino will not be as severe as it was in 1997-98 as ocean temperatures in the western Pacific were cooler at present.

If El Nino does return it could be politically significant with the coming of the Rio+10 conference in August.

It is the second high profile Earth Summit to be convened in Johannesburg, South Africa, after the first one 10 years ago in Rio De Janeiro.

Fear of 1997

The last El Nino took place in 1997-98 and was considered extremely severe when it caused withering drought in one country and rampant flooding in another.

In South Asia it was said to have caused delayed monsoons in India and severe flooding in Bangladesh.

Other phenomena observed with El Nino's appearance include forest fires in Indonesia.

These fires created a cloud of smoke that choked 20 million and affected Southeast Asian cities from Kuala Lumpur to Singapore.

In Australia it caused drought and bush fires as well as affecting areas of South China.

New Zealand suffered droughts on the east coasts of both the main North and South Islands, leading to lost production in a country heavily dependent on agricultural commodity exports.

La Nina

In late 1998, an episode of "La Nina" -- an unusual cooling of those same tropical Pacific waters -- led to a reversal of weather conditions.

During La Nina, drought prevailed in areas of the United States that had been drenched by El Nino.

"El Nino" -- Spanish for the Christ child -- was so named by Peruvian fishermen who noticed its greatest effects on the Pacific Ocean tended to occur around Christmas.

Climate historians have speculated that many significant events are linked to El Nino.

The U.S. "Dust Bowl" of the 1930's coincided with an unusually long lapse between El Nino events; the torrential Oregon rains which nearly finished off the Lewis and Clark expedition in the winter of 1805 took place during a major El Nino event.