Snowfall there "correlates inversely", according to the study, with rainfall in southwestern corner of Western Australia, which has seen a 15% to 20% drop since the 1970's. "The precipitation anomaly of the past few decades in Law Dome is the largest in 750 years, and lies outside the range of variability for the record as a whole, suggesting that the drought in Western Australia may be similarly unusual," finds the study. Australia's loss has been East Antarctica's gain, with increased snowfall there during the drought. "Only a single such (drought) event is expected in around 38,000 years for a climate unchanged from that of the past 750 years," write the authors, and should happen just once in 5,400 years, under normal conditions. The drought, they conclude, "lies outside the envelope of natural variability and supports the hypothesis of anthropogenically (man-made) induced climate shift."