Facing up to climate change

Primary industries need to face the fact that climate change is occurring – and develop strategies to adapt, according to the NSW Department of Primary Industries (DPI).

DPI’s Research Leader for Climate Science, Dr Helen Fairweather, says there is no doubt amongst credible scientists that climate change is a ‘real’ issue and that levels of CO2 in the atmosphere are rising.

“Even if we have some success in reducing greenhouse emissions, some climate change is inevitable”, she said. Dr Fairweather heads the DPI climate science research unit which will be carrying out research aimed at enhancing the capacity of primary industries in NSW to address climate change.

One of the Unit’s major projects is to “downscale” international and national climate change models, so that assessments of the potential impacts can be made at a regional and industry level.

Dr Fairweather says that although there is considerable uncertainty about potential climate change impacts, the scientific community as a whole is tending to agree that temperatures are rising.

“The extent to which they will rise depends on levels of greenhouse gas emissions.

“There is however less certainty about rainfall levels, with some model scenarios suggesting more rain and others less.”

One scenario puts United States agriculture as a net beneficiary of climate change.

Parts of Australia meanwhile are predicted to be worse off, as a result of having less and more variable rainfall, as well as more extreme climatic events.

Dr Fairweather says this highlights the fact that industries and markets may change, depending on how resilient agricultural systems are to climate change in different countries.

One recent study predicted that the inland winegrowing regions in the Murray Irrigation Area and Sunraysia could be adversely affected by an increase in growing season temperatures and shift in the time of harvest.

Dr Fairweather said the study highlighted the fact that if industries and regions had a clearer picture of the potential impacts of climate change, they could seek to take remedial action.

“This could include for instance breeding new plant varieties.

“We need to give industries some lead time to enable them to adapt to the changed circumstances.”

Dr Fairweather said at the moment it is difficult for industries to respond to climate change, given they do not have any certainty about how they will be affected.

”However, factors such as a longer growing season or changes in seasonal rainfall distribution will have important implications.

“They will affect adaptive strategies that primary producers might use, and may involve some changes to production systems.”

Dr Fairweather said extreme weather events are also predicted to increase.

“Over the next 30 years these extreme events may have a greater impact on agriculture than changes in average temperature or rainfall levels.

“They could result in extreme heat stress days for dairy cows or for livestock generally.”

Another area of concern is the impact of climate change on diseases, pests and weeds in agricultural systems.

She said answers were needed to questions such as whether the parasite risks to animals might increase.

Even the elevated level of CO2 in the atmosphere will have a direct effect on plants, irrespective of how it affects the climate.

For example, some plants are expected to suffer frost damage at temperatures 2 degrees C higher than at present, as a result of the atmospheric CO2 levels we expect in 30 years time.