Climate change presents a great threat to agriculture in Queensland. Industries reliant on natural resources will be the first to suffer the adverse impacts of a rapidly warming world.

Humans are producing unsustainable levels of greenhouse gas emissions from the burning of fossil fuels (like oil and coal) and the clearing of land. This is leading to an unnatural build up of these gases in the atmosphere, and a rapid warming of the earth, that is disrupting our climate system Unless action is taken to dramatically reduce greenhouse gas emissions, there could be a global average temperature increase of up to 5.8 oC (Intergovernmental Panel on Climate Change 2001).

The CSIRO has recently produced projections of future climate change in Australia. The map below sets out the future projected warming across Australia. Increased temperatures of up to 6 oC by 2070 will result in:

• higher temperatures;
• a reduction in crop and livestock quality and output;
• increased pests and weeds.

While there may be some benefits for some crops, the overall impact of climate change will be negative. A major finding in all studies is that a relatively small change in temperature (between 1 oC and 1.7 oC) causes a major change in regional climate patterns (CSIRO 2000).

One message is clear, climate change will fundamentally change agricultural production in Queensland.

Australia’s relatively low latitude makes it particularly vulnerable through impacts on its scarce water resources and on crops presently growing near or above their optimum temperatures. (Basher and Pittock 1998)

Rural communities, businesses and their representatives must assess the strength of current planning and policies dealing with climate change and agriculture. To do so, the causes and effects of climate change need to be fully understood throughout the community in terms of economic, social and landscape change.

The summary presented in this report intends to give an indication of the impacts of climate change on agriculture in Queensland, based on published scientific studies.

Ranges of average annual warming (C) for around 2030 and 2070 relative to 1990. Shaded bars show changes for areas with corresponding shades in the map.

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Climate change and temperature
It is predicted that increased temperatures will alter crop seasons, increase dairy and beef cattle heat stress, and introduce new pest and disease occurrences to Queensland.

Tables 1.1 and 1.2 (below) provide more detail about regional temperature increases likely in 2050 with climate change (Walsh et al. 2001).

One of the main outcomes from an increase in drought frequency is a predicted decrease in the average moisture of Queensland soils. (Walsh et al. 2001)

The range of possible temperatures presented in the Queensland study, and the most recent CSIRO projections, are a result of uncertainty about what will happen with global greenhouse emissions over the next few decades. If emissions continue to increase, the higher predictions of increases (of up to 6 oC across Australia by 2070) may be what farmers have to deal with.

Climate change, soils and water
Climate change will decrease the area of arable lands currently used for agricultural production in Queensland.

'One of the main outcomes from an increase in drought frequency is a predicted decrease in the average moisture of Queensland soils. This is a consequence of the greater evaporation caused by higher temperatures combined with rainfall that is not predicted to increase substantially.'
(Walsh et al. 2001)

The mean increases in drainage of 6-27mm/year represent a substantial potential change in landscape hydrology, which is likely to increase risks of salinisation in areas not yet affected, and increase rates of salinisation in areas already affected.
(Howden 1999b)

Evaporation will also have a negative impact on water storage, with greater losses from dams and increased risk of algal blooms. There is moderate confidence that climate change will also lead to a reduction in river and stream flow in Queensland.
(Walsh et al. 2001)

The CSIRO predicts average decreases in annual water balance, from lower rainfall and increased evaporation rates. By 2030 there may be decreases in moisture balance of up to 160mm, and up to 500mm by 2070, leading to greater moisture stress for Australia (CSIRO 2001). Extreme and intense rainfall episodes are also likely to increase in certain parts of Queensland, leading to increased problems with soil erosion and concomitant nutrient loss.
(Walsh et al. 2001)

Impacts on agricultural sectors

Beef cattle
The frequency of heat stress in Australian beef cattle increased by 40% from 1957 to 1996, and is estimated to increase by a further 138% by the year 2050 because of climate change.
(Howden 1999a)

Howden (1999a) predicts that an initial increase in temperature and atmospheric CO2 will increase pasture growth, live-weight gains and improved financial outcomes on the rangelands. However, increases in heat stress, water consumption, possible changes in grass distributions, and increased soil water logging and salinity, especially in marginal grazing lands, will offset the initial advantage.
(Howden 1999a)

Dairy cattle
CSIRO research predicts that there will be increased heat stress for dairy cattle in Queensland (Walsh et al. 2001), such that: by 2030, dairy cows without shade cover will suffer an average milk loss of 280L per cow per year (4% of annual production); and by 2070, dairy cows without shade cover will suffer an average milk loss of 250-400L per cow per year (6% annual production). (Jones and Hennessy 1999)

Wheat
The overall impact of climate change on wheat yields is likely to be negative. Increases in temperature, and reduction in rainfall, will outweigh the benefit of increased CO2 levels. Wheat yields are expected to decrease with warming beyond 2 oC, and with the expected reduction in rainfall as CO2 increases (Howden 1999b). Also, the predicted increase in CO2 levels is expected to reduce grain protein (or nitrogen) by 4-14%. These changes are likely to be significant in downgrading grain quality, representing a reduction in one to two quality classes.
(Howden 1999b)

Horticulture
Higher temperatures will decrease Queensland's suitability for producing fruits that require chilling to set (such as apples and stone fruit). This means that areas like the Southeast, where these fruits are currently grown, may need to look at growing different crops.
(Walsh et al. 2001)

There is an increased risk of fruit fly infestation in southern Queensland with higher temperatures.
(Walsh et al. 2001)

What can be done?
The vulnerability of Queensland's agriculture will be determined by community, individual and institutional readiness to help avoid climate change, and to adapt to it.

The speed and magnitude of global warming mean that rural communities have to consider a mix of mitigation and adaptation strategies. A strong government policy to
minimise the threat to rural communities and reduce greenhouse gas emissions is urgently needed. Such a policy must include commitments to the following.

Reducing Australia's greenhouse gas emissions from industrial sources

A dramatic reduction in emissions is required on a local and global level to protect agriculture from the worst impacts of climate change. In addition, government
must be lobbied to invest further in the transition to sustainable transport fuels, sustainable electricity generation (solar and wind), and energy efficient machinery and technology.

Including the effects of climate change in all future planning decisions for rural Queensland

Every policy and planning decision made for natural resources and agricultural planning must seek to reduce the effects of climate change on rural communities.

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Increasing funding for research into climate change impacts and mitigation strategies

CSIRO have produced world-class research into the effects of climate change and abatement strategies (such as methods to reduce methane emissions from livestock), however, there is currently very little government-funded research into the impacts of climate change on Queensland's rural communities.

Rejuvenating river systems

Healthy rivers will be more resistant to the effects of climate change. Water allocations must be planned, especially in irrigation districts, to mitigate the effects of climate change. Environmental flow allocation must be protected to ensure continuing water quality and river health in the future.

Expanding native vegetation regeneration, and halting land-clearing rates

Current best practice mitigation for salinisation is the reintroduction of native, stabilising ecosystems. A strongly funded and enacted native vegetation strategy to combat salinisation is needed to reduce the vulnerability of salinity-affected farmers in the future. Halting land-clearing rates will also lead to a decrease in greenhouse gas emissions.

For more information Contact:
Queensland Conservation Council
(07) 3221 0188 or at www.qccqld.org.au

Climate Action Network Australia

Join the Farming and Climate Change network by logging on to: www.cana.net.au/farmer/

Produced with assistance from the Myer Foundation.

References
Basher, R. E. & Pittock, A. B. 1998, 'Australasia' (Chapter 4), in The Regional Impacts of Climate Change: An Assessment of Vulnerability, Watson, R. T., Zinyowera, M. C., Moss, R. H. & Dokken, D. J., Cambridge University Press, New York.

Bureau of Rural Resources 1989, Rural Industries: Workshop on Climate Change, Bureau of Rural Resources, Canberra.

CSIRO 2000, Inquiry into Global Warming, Submission to the Senate Environment, Communication, Information Technology and the Arts Reference Committee, Canberra.

CSIRO 2001, Climate Change Projections for Australia, Climate Impact Group, CSIRO Atmospheric Research, Melbourne.

Hennessy, P. K., Whetton, P. H., Katzfey, J. J., McGregor, J. L., Jones, R. N., Page, C. M. & Nguyen, K. C. 1998, Fine Resolution Climate Change Scenarios for NSW: 1995-1998, Summary Report, Research undertaken for the NSW EPA, CSIRO Atmospheric Research, Canberra.

Howden, S. M., McKeon, G. M., Reyenga, P. J., Carter, J. O. & Scanlan, J. C. 1999a, Global Change Impacts on Australian Rangelands, Report to the Australian Greenhouse Office, CSIRO Wildlife and Ecology, Working Paper 99/09, Canberra.

Howden, S. M., Reyenga, P. J. & Gorman, J. T. 1999b, Global Change Impacts on Australian Wheat Cropping, Report to the Australian Greenhouse Office, CSIRO Wildlife and Ecology, Working Paper 99/04, Canberra.

Howden, S. M., Reyenga, P. J. & Meinke, H. 1999c, Global Change Impacts on Australian Wheat Cropping: Studies on Hydrology, Fertiliser Management and Mixed Crop Rotations, Report to the Australian Greenhouse Office, CSIRO Wildlife and Ecology, Working Paper 99/13, Canberra.

IAWG 2001, Climate Change Impacts for Australia, CSIRO Impacts and Adaptation Working Group, CSIRO Sustainable Ecosystems, Aitkenvale QLD.

Intergovernmental Panel on Climate Change (IPCC) 1998, in The Regional Impacts of Climate Change: An Assessment of Vulnerability, Watson, R. T., Zinyowera, M. C., Moss, R. H. & Dokken, D. J., Cambridge University Press, New York.

Intergovernmental Panel on Climate Change (IPCC) 2001a, Working Group I, Third Assessment Report, Shanghai Draft 21/1/2001, Summary for Policy Makers, IPCC, Shanghai.

Intergovernmental Panel on Climate Change (IPCC) 2001b, Working Group 2, Third Assessment Report, 'Australia & New Zealand' (Chapter 12), Final Government Distribution.

Jones, R. & Hennessy, K. 1999, Climate Change Impacts in the Hunter Valley: A Risk Assessment of Heat and Stress Affecting Dairy Cattle, citing Davison et al. 1996, Managing Hot Cows in Australia, QLD Department of Primary Industry, p. 58.

Pittock, B., Evans, D. & Jakeman, T. 1999, Climate Change and Rural Water Supply, CSIRO, Canberra.

Walsh, K., Hennessy, K., Jones, R., McInnes, K., Page, C., Pittock, B., Suppiah, R., Whetton, P. 2001, Climate Change in Queensland under Enhanced Greenhouse Conditions, Third Annual Report 1999-2000, CSIRO Atmospheric Research.