Pacific droughts, floods to intensify
CLIMATE change will lead to more extreme floods and droughts in the South Pacific as the southern hemisphere’s largest rain band responds to increasing greenhouse gas emissions, an international study has found.
The study, led by CSIRO oceanographer Dr Wenju Cai, examined the movement of the South Pacific rain band, which spans the Pacific from south of the equator southeast to French Polynesia and can move north up to 1000km towards the equator.
It found the frequency of this movement will almost double in the next 100 years, with rain intensifying at a corresponding rate.
“South Pacific countries will experience more extreme floods and droughts, in response to increasing greenhouse gas emissions,” the CSIRO says in a statement that cites the report paper published in journal Nature today (Thursday, August 16).
The study found greenhouse gases are projected to enhance equatorial Pacific warming, which will lead to increased frequency of extreme excursions of the rain band.
It is the largest and most persistent rain band in the southern hemisphere.
“During extreme El Nino events, such as the 1982-83 and 1997-98, the band moved northward by up to 1000km,” says Dr Cai.
“This shift brings more severe extremes, including cyclones to regions such as French Polynesia that are not accustomed to such events.”
During moderate El Nino events the rain band moves northeast by 300km and countries located in its normal position, such as Vanuatu, experience forest fires and droughts and increased tropical cyclones, the study found.
Countries to which the band moves experience extreme floods.