March 24, 2009

Research Questions Climate Change Link To El Nino Events

A 1918 El Nino event may have been much more intense than experts previously considered, according to new research.

Ben Giese and his colleagues of Texas A&M University used computer models to show the 1918 El Nino was almost as strong as that of 1982/83 and 1997/98, which resulted in deaths, lost crops and infrastructure damage.

An El Nino is associated with floods, droughts and major economic damage worldwide. It is the result of intense warming that extends over the tropical Pacific. As rains concentrate over the western Pacific and shift to the east, many parts of Australia, Southeast Asia and India suffer from intense droughts.

Meanwhile, the events can cause flooding in Chile and Peru as well as colder, wetter winters in the southern US.

Being able to predict and determine the causes of El Nino events is of major concern to climatologists.

Giese told Reuters that his team's finding "questions the notion that El Ninos have been getting stronger because of global warming."

The 1918 event also coincided with one of India's worst droughts of the 20th century, he found.

"We know that El Ninos and drought in India are often related to each other," he said.

Droughts in Australia during 1982-83 and 1997-98 were among the worst on record. Droughts were also reported in eastern Australia from 1918-20.

Giese's team analyzed data from an atmospheric model produced by the National Oceanic and Atmospheric Administration (NOAA) to simulate oceanic temperatures and conditions during 1908 to 1958.

Giese told Reuters that there is a lack of data from the tropical Pacific during 1918, which was the last year of World War I.

Giese said this supports the idea that there is limited data about El Ninos prior to the 1950s and that computer models were one way to get a clearer picture of the past.

"We cannot rely on what El Nino looks like today to try to understand what El Nino patterns looked like in the past."

"It makes it a challenge to talk about El Nino and global warming because we simply don't have a detailed record," he said.


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