A new El Nino has begun, meteorologists have said.

They confirmed that the sporadic Pacific Ocean warming, which can disrupt weather patterns across the world, is intensifying.

As a result, there may be increased drought in Africa, India and Australia, heavier rainfall in South America and increased extremes in Ireland, of warm and cold, in the coming months.

The cyclical phenomenon, which happens every two to seven years, is a major determinant of global weather systems. The 1997-98 El Nino combined with global warming to push 1998 into being the world's hottest year, and caused major droughts and catastrophic forest fires in south-east Asia.

At present, forecasters do not expect this El Nino to equal that of 1998, but concerned groups, from international insurance companies to aid agencies such as Oxfam, have begun to follow its progress anxiously.