New research from the CSIRO suggests the current drought is due to natural variation in climate, not the greenhouse effect.
Barrie Hunt, an honorary research fellow at the CSIRO's atmospheric research centre in Melbourne, has studied 10,000 years of climate variability in Australia.

His research shows about 30 periods of drought which occur at random times and he says the length of each drought does not follow a predictable pattern.
Mr Hunt says this drought is not caused by the greenhouse effect.
"I think it's probably a bit too early yet to say we're having a greenhouse effect on rainfall, rainfall's a very difficult climatic term to get to grips with," he said.
"There's definitely a greenhouse effect on temperature; I'm not sure we're having one on rainfall yet.
"This drought will break and it's important for people to say, 'Well, I understand that when the drought breaks, it's not the greenhouse effect. It's a load of rubbish, of course - it's rained again'.