PERTH (Reuters) - Australia could experience more severe droughts and they could become more frequent in the future because of climate change, a government-commissioned report said on Sunday.

Droughts could hit the country twice as often as now, cover an area twice as big and be more severe in key agricultural production areas, the Bureau of Meteorology and Australia's top science organization, the CSIRO, said in a joint report.

The study also found that temperatures currently defined as "exceptional" were likely to occur, on average, once in every two years in many key agricultural production areas within the next 20 to 30 years, while spells of low rainfall would almost double in frequency from current figures.

Australia, suffering its worst drought in 100 years, has seen its wheat exports tumble in the past two years.