Warming will change Pacific climate

Shifting rain patterns due to greenhouse gas emissions mean South Pacific countries could experience either extreme floods or droughts, researchers say. The changes will result from the South Pacific rain band responding to greenhouse warming, they said, sometimes moving hundreds of miles northward toward the equator and inducing extreme climate events. The South Pacific rain band is largest and most persistent in the Southern Hemisphere, spanning the Pacific from south of the Equator southeastward to French Polynesia. The international study, led by oceanographer Wenju Cai of the Commonwealth Scientific and Industrial Research Organization of Australia, suggests the frequency of movement of the rain band will almost double in the next 100 years with increased greenhouse gas emissions, with a corresponding intensification of weather events. Increases in greenhouse gases are projected to enhance equatorial Pacific warming and El Nino events. "During extreme El Niño events, such as 1982/83 and 1997/98, the band moved northward by up to 1000 kilometers (600 miles,)" Cai said. "The shift brings more severe extremes, including cyclones to regions such as French Polynesia that are not accustomed to such events." Countries located within the bands' normal position such as Vanuatu and Samoa may experience forest fires and droughts as the band moves north away from them, the researchers said, whereas countries to which the rain band moves may experience extreme floods. The results of the study were published in the journal Nature.