La Niña in sight
The latest data regarding conditions in the equatorial Pacific Ocean show that the El Niño event of 1997/98 has passed its peak and there is evidence that the next La Niña — El Niño’s mirror image — may follow more swiftly than usual.
The El Niño event of 1997/98 brought unprecedented climate stress to many parts of the world and its full impact is only now being assessed. As health statistics for 1997 are analysed, the World Health Organization (WHO) reports that nearly 150,000 cases of cholera were reported that year with heavy rains in Africa, linked to El Niño, thought responsible for around 80 per cent of the total. Fatality rates reached 20 per cent in some countries.
Eastern Cuba faced drought as 1998 progressed after spring and early summer rainfall was halved during the final stages of the latest El Niño. Braulio Lapinel of the National Meteorological Institutes estimated April-June rainfall as the poorest since 1941. Heavy rain during this period is essential for sugar cane. Staple crops such as root vegetables, beans, bananas and rice have been severely affected in some areas as well as livestock, poultry and dairy production. The government has requested food aid from the United Nations to alleviate the situation.
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© 1998 Lawrence Moore |
La Niña is the opposite phase of the phenomenon with warm temperatures in the equatorial Pacific replaced by cool and the nature of the climate disruption elsewhere in the tropics and sub-tropics reversed. Usually, there is some respite between the two phases but there are indications that La Niña may, this time round, follow hard on the heels of the record-breaking El Niño event. Lars Olsson of the World Climate Programme warned that “La Niña is developing rapidly. This one seems more intensive than what we have seen before.”
La Niña brings wet weather and flooding to Southeast Asia and parts of Australia, drought to the US west coast and South America and can lead to an increase in tropical storms in some areas. The swift arrival of La Niña could compound existing problems. “After severe droughts the top soil is very fragile and if you get heavy rain on the top soil, then you could get heavy erosion,” Olsson pointed out. La Niña may, however, bring an end to widespread forest fires and smog in Southeast Asia.
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El Niño and the Southern Oscillation