The results also argued that events based on extreme sea-surface temperatures had increased during the past 60 years compared with the 1901-60 period,and large so-called El Nino-Southern Oscillation (ENSO) events since the mid-20th century were larger than any time during the past few centuries.
Those findings,though,were at odds with the IPCC report,which argued there was a “medium confidence” that “there is no model consensus for a systematic change in intensity of ENSO sea surface temperature variability over the 21st century in any of the[carbon emissions] scenarios assessed”.
The IPCC’s verdict surprised the paper’s lead authors,Wenju Cai from the CSIRO,and Agus Santoso,a climate researcher based at the University of NSW. While their paper missed the January cut-off to be considered by the IPCC for its report,it was based on model data already available for IPCC reviewers.
“Most of the models are showing sea-surface temperature variability” as a driver of future extreme events,Dr Cai said. “I don’t know how they missed it.”
Dr Santoso said:“It’s quite surprising to me as well,” and “monster El Ninos will start appearing”.
Understanding how El Ninos and La Ninas will change in a warming world will be vital. Although the weather patterns emanate in the Pacific,they have global impacts,ranging from droughts and bad bushfire seasons in Australia,to altered rainfall patterns in California and the Brazilian Amazon.