BLAME the Indian Ocean for Australia’s “Big Dry” – the intense drought that has dried out much of the Murray-Darling river system, devastated agriculture and led to water rationing in Melbourne.
Until now, the Big Dry and two other major droughts to hit south-east Australia – the Federation Drought from 1895 to 1902 and the second-world-war drought – have been blamed on the El Niño Southern Oscillation (ENSO), which is a cyclical change in sea surface temperatures in the tropical eastern Pacific Ocean. But when Caroline Ummenhofer of the University of New South Wales in Sydney and colleagues compared records from…
