"Models and physical reasoning predict that extreme precipitation will increase in a warmer climate due to increased atmospheric humidity"
" The strongest extremes (99.9th percentile events) scale significantly faster than near-surface water vapour, between 5.7–15% °C−1 depending on model details. This scaling rate is highly correlated with the change in water vapour, implying a trade-off between a more arid future climate or one with strong increases in extreme precipitation. "
http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate3201.htmlSo because AGW, Climate Change, in future it will be more rain, less rain or something in between.
From UNSW.
"Steve Sherwood, a professor at the Climate Change Research Centre at the University of NSW who contributed to the research, said global warming would have a clear impact on rainfall.
"There is no chance that rainfall in Australia will remain the same as the climate warms," he said.
"With two degrees of global warming, Australia is stuck with either more aridity, much heavier extreme rains, or some combination of the two." "
http://www.theleader.com.au/story/4407668/more-rain-on-the-horizon-as-climate-ch...