The climatic extremes experienced recently in Australia are expected to continue, a new study of long-term climate trends by the CSIRO and the Bureau of Meteorology has warned.

The State of the Climate 2012 report predicts an increase in the number of droughts in southern Australia, coupled with an increase in intense rainfall events in many areas.

The report identifies a trend towards increased spring and summer monsoonal rainfall across Australia’s north, higher than normal rainfall across Central Australia and a decline in late autumn and winter rainfall across southern Australia.

But no significant trends for the total numbers of tropical cyclones or for the occurrence of the most intense tropical cyclones have been found in the Australian region.

The data shows that since the 1950s each decade has been warmer than the previous decade, with Australia’s annual average daily maximum temperature increasing by 0.75 °C since 1910, and the annual average overnight minimum temperature increasing by more than 1.1 °C in the same period.

In line with this trend, Australian average temperatures are projected to rise by 1-5 °C by 2070.

But due to the recent La Nina weather pattern, 2010 and 2011 were Australia’s coolest years since 2001.

Australian sea-surface temperatures – which are affected by La Nina – were found to be the highest on record in 2010, with local sea-surface temperatures increasing by about 0.8 °C since 1910, at a rate faster than the global average.

CSIRO CEO Megan Clark says the report paints a clear decade-to-decade picture of Australia's climate, while at the same time noting its highly variable nature from one year to the next.

“Much of Australia may have lurched from drought to floods since the previous State of the Climate report, but this has occurred against a backdrop of steadily increasing air and ocean temperatures and rising sea levels,” Dr Clark says. “What’s more, the rate of change is increasing.”