El Niņo 'could return in months'

The last El Niņo brought forest fires to the Philippines

By BBC science correspondent Richard Black

Weather forecasters in the United States say they have found evidence that an El Niņo event is starting.

The forecasters, from the US Government's National Oceanic and Atmospheric Administration (Noaa), predict that El Niņo could be influencing the weather by early spring.

What is El Niņo?

Means "the little boy" in Spanish

An unusual warming of the oceans during some winters linked with higher rainfall

Parts of the Pacific Ocean warm and change weather patterns around the world

First noticed by South American fishermen when fish catches went down

The last event, in 1997 and 1998, had serious effects on several regions of the developing world.

The root cause of an El Niņo event is a warming of water in the eastern Pacific Ocean. This rise disturbs the pattern of ocean currents, in turn affecting wind and rain.

The US forecasters have found a characteristic temperature rise in the eastern Pacific and say the El Niņo could be with us within four months. They say that at the moment it is impossible to predict how significant the changes in weather will be.

"The magnitude of an El Niņo determines the severity of its impacts," said Vernon Kousky, Noaa climate specialist.

"At this point, it is too early to predict if this El Niņo might develop along the same lines as the 1997-98 episode, or be weaker."

Drought and famine

The 1997/1998 event was one of the most severe on record, and had a number of devastating environmental impacts.

Floods in western South America and parts of Africa led to several thousand deaths and shortfalls in the main crops.

Schools were closed because of smog

East Asia experienced a drought leading to severe forest fires and smog, resulting in several billion dollars' worth of lost economic output.

Other meteorologists confirm the North American data. They say that as El Niņos occur on average once every four years. This one is not unexpected.

Scientists who model global climate change predict that if our planet continues to slowly warm up, we will see more frequent and more severe El Niņo episodes.

Researchers will be monitoring the latest El Niņo closely for anything it can tell us about long-term climate change.