Tuesday, March 24, 2009

El Nino study challenges global warming intensity link

Reuters: Research showing an El Nino event in 1918 was far stronger than previously thought is challenging the notion climate change is making El Nino episodes more intense, a U.S. scientist said on Tuesday. El Nino causes global climate chaos such as droughts and floods. The events of 1982/83 and 1997/98 were the strongest of the 20th Century, causing loss of life and economic havoc through lost crops and damage to infrastructure.

But Ben Giese of Texas A&M University said complex computer modelling showed the 1918 El Nino event was almost as strong and occurred before there was much global warming caused by the burning of fossil fuels or widespread deforestation.

The outcome of the research was valuable for several reasons, Giese told Reuters from Perth in Western Australia. "It questions the notion that El Ninos have been getting stronger because of global warming," he said ahead of a presentation of his team's research at a major climate change conference in Perth. The 1918 event also coincided with one of India's worst droughts of the 20th century.

…[T]here 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 added.

Chart of abnormal ocean surface temperatures [ºC] observed in December 1997 during the last strong El Niño. NOAA

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