Agriculture and Food Supply

The forces that shape our climate are also critical to farm productivity

The National Farmers’ Federation has suggested that climate change is possibly the biggest risk facing Australian farmers over the coming century

Temperature: An increase in average temperature can affect:

Rainfall, floods and severe storms: Changes in rainfall can affect:

Top of Form

Bottom of Form

Food and Fiber

the response of dairy cattle to heat stress

heat stress in beef cattle

Physiological effects of heat stress include

  • reduced food intake

  • weight loss

  • decreased reproduction rates

  • reduction in milk yields

  • increased susceptibility to parasites

  • in extreme cases, collapse and death

  • heat stress already has increased significantly in subtropical Queensland over the past 40 years (where there has been a warming trend)

  • it will increase further with greenhouse-induced global warming

Howden and Turnpenny (1997) and Howden et al. (1999e)


How will agriculture adapt to a shifting climate?

The agriculture sector is vulnerable to the potential impacts of climate change including:

the likely impacts on different types of agriculture.


Some potential impacts from climate change


  • increased crop water-use efficiency due to higher carbon dioxide concentrations but potentially reduced grain quality

  • reduced water availability due to both reduced rainfall and increased evaporation

  • reduced crop yield

  • changes to world grain trading

  • increased risk of pests, parasites and pathogens


  • changes to frost frequency and severity may cause lower yields and reduced fruit quality

  • damage from more extreme events such as hail, wind and heavy rain

  • increased risk of pests and disease

  • warmer conditions may impact on chilling requirements of some fruit cultivars


  • higher ripening temperatures may reduce optimum harvesting times

  • potential changes to phenology and wine quality

  • warmer conditions may allow new varieties to be grown in some areas

  • reduced water supply for irrigated crops

  • investment impacts due to long investment cycles

Grazing & livestock

  • increased growth from higher carbon dioxide levels but potentially offset by reduced rainfall and higher temperatures

  • higher temperatures reducing milk yields

  • decreases in forage quality

  • increased rainfall variability reducing livestock carrying capacity

  • heat stress in Northern Australia impacting on productivity and animal welfare

  • increased risk and rates of salinisation in some areas

  • increased risk of pests, parasites and pathogens

Heat Stress in Corn – poor kernel formation A9b_s1_2

Examples of climatic sensitivities in agriculture

Annual cropping

The grains industry, Australia’s largest crop based industry, is sensitive to the timing of frosts, sowing

rains and rain in spring. In addition, cumulative temperature impacts may be important, as well as

increases in wind speed.

Dairy cattle

The dairy industry is vulnerable to climate change, especially because of the sensitivity of dairy

cattle to heat stress (high temperature coupled with high humidity).

Sheep and beef cattle

The timing and seasonal patterns of rainfall are important for pasture based livestock industries.

The extensive beef production industry has learned to cope with regionally variable rainfall; it is

more adaptable than many rural industries. For the sheep industry, cold events (wind, rain, and low

temperature in combination) are a common risk for recently shorn and new born animals.


Hail storms and frosts are major climatic risks for the fruit industry.

For apples and pears, the timing of rainfall is important; in dry conditions the availability of irrigation water is crucial. Higher night temperatures can be a problem for some late harvested varieties of fruit.


For the viticulture industry, the timing of rainfall is critical. Late summer rainfall can lead to splitting,

ringing, disease exposure and rot. Generally wet summer conditions can lead to fungal and bacterial

infection from the soil. Frosts at bud burst and fl owering can also devastate yields.

Source: Steffen and Sims (2006).

World's Most Important Crops Hit
By Global Warming Effects 23 March, 2007