Climate change and agricultural productivity

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This project area examines the impact of climate change on the production of major primary products in Australia and abroad.

• Increases in atmospheric CO₂ concentrations are beneficial for plant growth, however, increased greenhouse gas concentrations are driving climate change, specifically decreases in annual average rainfall and increases in annual average temperature.



• Predictions from models of temperature increases suggest a wide range of uncertainty—ranging from 0.4–2.1°C by 2030, to 6.8°C in 2070 (CSIRO 2001, Lindesay 2003)
  
  Temperature increase diagram: Climate Change projections for Australia (Beeton et al., 2006) on the Australian Government's Department of Environment and Water Resources website: [External html]
  



• Wheat is the staple food of almost half the world's population and is one of the most important commodities produced by the Australian agricultural industry



• Given the extremely slow progress in international climate agreements to reduce emissions, regional adaptation to climate change, is the main and cheapest option to reduce impacts of global warming (Porter et al., 2007)



• Increased water use efficiency under elevated CO₂ is more strongly exhibited in C₃ plant species such as wheat and grain legumes with a reported 30% increase yield in wheat in response to doubling of atmospheric CO₂ concentrations (Ainsworth & Long, 2005)(Amthor, 2001).



• Of all the inhabited countries of the world, the relative CO₂ fertilisation effect is likely to be most important for rainfed broadacre agriculture in Australia (Steffen and Canadell, 2005).




• Model-based predictions by wheat and barley confirm that any increase grain production under elevated CO₂ will be counterbalanced by both water and N limitations (Grace 2006, 2007).
  
  Wheat Presentation: Link [Powerpoint Show]
  Barley Presentation: Link [Powerpoint Show]
  



• An additional 25 kg N ha^-1 would be required (with current cultivar selection) to close the yield gap alone, even after yields are compensated by the effects of elevated CO₂ (Grace, 2006).
  
  Related publication: Wheat Production Systems and Climate (Grace, Jamieson and Porter 2007): Link [PDF]
  
  

References

Amthor, J.S., 2001. Effects of atmospheric CO₂ concentration on wheat yield: review of results from experiments using various approaches to control CO₂ concentration. Field Crops Res., 73, 1-34.

Ainsworth, E.A. & Long, S.P., 2005. What have we learned from 15 years of free-air CO₂ enrichment (FACE). A meta-analytic review of the responses of photosynthesis, canopy properties and plant production to rising CO₂. New Phyto., 165, 351-372.

Beeton, R, Buckley, K, Jones, G, Morgan, D, Reichelt, R, Trewin, D 2006, Australia State of the Environment 2006. Retrieved September 25th 2007, from http://www.environment.gov.au/soe/2006/publications/report/atmosphere-3.html

CSIRO, 2001, Climate Change Projections for Australia, CSIRO Atmospheric Research, http://www.cmar.csiro.au/e-print/open/projections2001.pdf

Grace, P.R., 2006. Farming in a changing environment. Plenary address. Grains Week, Grains Council of Australia, Canberra, Australia, April 5-6, 2006.

Grace, P.R., 2007. Climate change and barley production – Eastern Australia perspective, 13th Australian Barley Technical Symposium, Fremantle, Australia, 28-30 August, 2007.

Lindesay, J.A., 2003. Climate and drought in Australia. In Botterill, L.C. and Fisher M. (Eds) Beyond Drought: People, Policy and Perspectives, CSIRO Publishing, Collingwood, Victoria.

Porter, J.R., Jamieson, P.D., & Grace, P., 2007. Wheat production systems and climate. In: J. Canadell et al. (Eds) Terrestrial Ecosystems in a Changing World. The IGBP Book Series, Springer-Verlag, Berlin, pp. 195-209.

Steffen, W. & Canadell, J.G., 2005. Carbon dioxide fertilisation and climate change policy. Australian Greenhouse Office, Canberra.


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