August 4, 2010

Climate change threatens Australia's agricultural land

Land available for agriculture in Australia, one of the world's largest food exporters, is in danger of contracting amid climate change, according to a leading scientist.

More grain was also likely to be grown in the north as climate change cuts production in the drier south with more marginal areas turned over to pasture, threatening Australia's position as the world's fourth largest grain exporter.

The country's mostly infertile and fragile soils made the agriculture industry particularly vulnerable to climate change, said director of the Climate Adaptation Flagship project of the government-backed research organisation CSIRO.

"We've had a fairly strong drying trend over the past 12 years or so and we think now there is a climate change signal associated with that," Ash said.

He said major changes in land management were needed to keep the 60% of Australia's land mass now used for agriculture from shrinking.

"It is more likely that we will see some cropping areas at the margins shrink," he said, while other areas would expand in regions that now have high rainfall, such as parts of Victoria, but which are expected to become drier. This might make these areas more suitable for cereal crop production, he said.

Australia is also expected to become warmer in the coming decades, further limiting water availability to crops and run-off for rivers and dams, particularly in the south, as well as escalating the risk from bushfires.

This would also affect soils because they help in the cycling and storage of water, nutrients such as nitrogen and phosphorus as well as carbon dioxide, the main greenhouse gas.