Strategic adaptation needed to a reduction in rainfall, which could close farms or shift them towards wetter coastal areas

Australia needs a better response to drought in the face of climate trends that will transform agricultural regions and see many farms disappear, the CSIRO has warned.

The government’s science agency said that observed changes in rainfall are occurring at a more rapid rate than was previously predicted. These changes could see a continuing trend of farm closures and shift farming towards wetter coastal areas.

Tony Abbott has just completed a “listening tour” of drought-affected areas of Queensland and NSW, meeting farmers who haven’t had significant rainfall for nearly two years. The government is putting together an assistance package for farmers, although Abbott has dismissed any link between drought and climate change.

In 2007, the CSIRO and Bureau of Meteorology made a number of predictions around annual rainfall to 2070, based on three different global warming scenarios. Even under the low emissions scenario, vast areas of Australia, including much of Victoria and Western Australia, are set to experience much less rainfall by 2070. Separate modelling by CSIRO shows WA will bear the heaviest reduction in rainfall up to 2070.

Rainfall projections under low, medium, and high emission scenarios for different seasons, modelled by CSIRO and BoM based on IPCC scenarios.

Evaporation rates, caused by extremely warm days, are also expected to soar, particularly in eastern and northern Australia.

How evapotranspiration (a combination of evaporation from soil, plant and other sources) may vary under different climate change scenarios. Modelled by CSIRO and BoM based on IPCC scenarios

BoM records for the past year, animated by Guardian Australia , show that record rainfall lows have been experienced across much of central Queensland, Northern Territory, South Australia, Victoria and WA.

Animated map showing rainfall deficiencies for a rolling 6 month period, over the past 12 months. Source: Bureau of Meteorology

Steve Crimp, senior research scientist for the CSIRO’s Climate Adaptation Flagship, told Guardian Australia that the latest data shows Australia will experience 7% to 20% less annual rainfall by 2030, depending on the amount of carbon emissions pumped into the atmosphere.

“We are already seeing significant declines in the number of farmers in Australia and the size of farms increase,” he said. “We will see a continuation of that trend, with fewer and fewer farms over a larger area in the future.

“The observed trends are more severe than was previously modeled. Some areas of WA are seeing changes in rainfall that were expected in 2030. We’ll expect to see Australia’s wheat belt move towards the coast in response to future changes.”

Crimp said climate change will have an indirect impact on drought by altering the El Nino effect, which influences rainfall in Australia. El Nino events push established rainfall bands out into the ocean, reducing the amount of rain falling on Australia’s land mass.

“We are already seeing farmers shift between cropping and grazing and using different soil types,” he said. “But the significant challenges for agricultural production mean that there will have to be a move towards systemic and transformational change.

“The issue that concerns me is that adaptation is reactive at the moment. As the rate of change accelerates, being responsive won’t be the most cost effective thing to do. We need a more strategic approach to adaptation, otherwise we will always be behind the eight ball.”

The government’s drought package is expected to include help for farmers to get low interest loans, as well as better access to social services.

Tim Flannery of the Climate Council told Guardian Australia that farmers need to diversify, rather than just get financial help.

“Australian farmers face one of the most variable and harsh climates in the world and there’s no doubt there are times when they need assistance,” he said. “But as conditions change, the one thing you don’t want to do is create a rural constituency that’s dependent on government handouts for survival.

“Some may need to leave but there are other options, to grow heat-tolerant crops or to diversify. If you have six wind turbines on your property, for example, you’re making $60,000 a year regardless of the conditions.”

The BoM said it expects there to be a future increase in the number of droughts in southern Australia but also an increase in intense rainfall events in many areas, especially in the north.

“The current drought is meteorologically significant, but well within the range of historical experience,” said BoM climatologist Blair Trewin. “In a broad sense, it can probably be characterised over most of the affected areas as a drought year of an intensity that’s typically expected once in 10 to 20 years, although some individual locations have fared more badly.”