Australia weather extremes likely to worsen: report

* Hotter Australia faces more intense rains, droughts
* Warmer seas, rising ocean levels further threats - report
* More chaotic weather a challenge to miners, farmers
David Fogarty Reuters 14 Mar 12;

SINGAPORE, March 14 (Reuters) - Australia, one of the world's top mining and agricultural nations, faces a quickening pace of climate change, according to a snapshot of the nation's weather, forcing farmers to alter cropping strategies and miners to cope with more intense floods.

The government report released on Wednesday confirms the changing trends in rainfall and warmer temperatures across Australia, to which farmers are adapting by growing new crop varieties and adjusting planting times.

Coal and iron ore miners are building bigger holding dams for flood waters, and strenthening road and rail infrastructure, while coastal communities are being told to prepare for rising sea levels.

The report, compiled by the Bureau of Meteorology and the Commonwealth Scientific and Industrial Research Organisation (CSIRO), looks at long-term climate trends in Australia. Its release comes after 18 months of record rains in the country's east, triggering floods that ended a devastating drought.

Australia is getting hotter, the pace of sea level rise quickening, the oceans warming and rainfall patterns shifting towards more rain in the summer, the report said.

Each decade has been warmer than the previous decade since the 1950s, it said, with rising greenhouse gas emissions from burning fossil fuels, deforestation and agriculture blamed for the changes.

"We're certainly seeing where the rain is falling is changing," Megan Clark, CSIRO's chief executive, told Reuters. "We're seeing more in spring and summer ... a monsoonal signature across Australia's north, and more rainfall in central Australia," she said.

"And from the agricultural point of view, less autumn and winter rain across the south."

The report is only the second joint climate snapshot, with the first released in 2010 before the start of an intense La Nina event that triggered months of flooding, crimping economic growth and causing billions of dollars in insurance losses.

Australia is the world's top coal exporter, a major iron ore producer and fourth largest wheat exporter, sectors at risk from more chaotic weather.

IN HOT WATER

A second, weaker La Nina in 2011 brought more rains. On Tuesday, the Bureau of Meteorology said the event was coming to an end, but rainfall in parts of Australia could still be above average.

La Nina is a periodic warming of the Western Pacific Ocean. It normally triggers above average rains and cooler weather across northern and eastern Australia and Southeast Asia. The opposite phenomenon, El Nino, usually brings drought and warmer weather.

Clark said 2010-11 stood out for the peak rains and the equally record-breaking sea surface temperatures around northern Australia.

"This consistent rise in our sea surface temperatures has been a bit surprising," sshe said.

"The other thing we're seeing is when the conditions are right for rain, we're getting a lot of rain."

The report shows minimum Australian temperatures at night have warmed by more than 1.1 degrees Celsius since 1910, with most of this since 1960, and that the rate of very hot daytime temperatures, higher than 40 degress C, has been increasing since 1990.

Sea levels since 1993 around Australia's north and northwest have been rising 7 to 11 millimetres a year, two to three times the global average.