The agricultural sector, which accounts for almost one fifth of Australian greenhouse gas emissions, is particularly vulnerable to the effects of global warming. Changes to rainfall, temperature, storm intensity and drought frequency will increase evaporative water loss, increase soil erosion, stress livestock, damage crops, exacerbate fire risks and imperil fish stocks. This threatens the identity and livelihoods of more than half a million Australians directly reliant on fishing, farming and grazing.

In 2003 the National Greenhouse Inventory showed that the agricultural sector, contributed 18% of Australia's net greenhouse gas emissions. Methane emissions from livestock, known as enteric fermentation, are the largest single agricultural contributor to greenhouse gas emissions, followed by land use changes (i.e. clearing vegetation for cropping, silviculture or grazing), and emissions associated with disturbance of agricultural soils. While land clearing has declined significantly in the period from 1990-2003, agricultural emissions grew by 4% (ibid).

The National Farmers Federation has described climate change as a major risk to farmers this century, with IPCC predictions of a possible increase in global average temperature of between 1 and 6ΊC by the year 2070. In 2004, the Western Australian Farmers Federation publicly announced their support of the Kyoto Protocol as a mechanism to reduce greenhouse gas emissions and urged the federal government to ratify the agreement. This significant change in the position of the Farmers Federation is testament to the extreme impacts of climate change, in particular reduction in rainfall, on the agricultural sector.

The Australian Greenhouse Office's Guide to Climate Science and Impacts records the following consequences of climate change:

• a decrease in available water resources;
• higher temperatures and hence evaporation;
• increased heat stress of livestock causing reduced weight and milk yields;
• reduction in chilling cultivars, viticulture (vineyard yield);
• damage of crops from extreme weather, increased pests and disease outbreaks;
• a reduction of area of arable land from the 'dustbowl effect" and;
• a reduction in crop yield and quality.

The Australian Greenhouse Office report on Risk and Adaptation lists the following agricultural sectors as most at risk:

• those already stressed - economically or biophysically, as a result of land degradation, salination and loss of biodiversity;
• those at the edge of their climate tolerance; and
• those where large and long lived investments are being made - such as in dedicated irrigation systems, slow growing cultivars and processing facilities.

Dependence on water by the farming industry makes climate change a huge challenge for farming. Covering approximately 60% of Australia, the agricultural sector uses more land and water than any other domestic industry, with estimates in the Water Account Australia 2000-01 that agriculture accounted for 67% of water consumption in 2000-01.

As a result of the dependence on irrigation, the agricultural sector is particularly vulnerable to frequent drought and high evaporative loss of stored water. The combination of rising average temperatures and more intense droughts (and floods) will have significant adverse impacts upon the viability of Australian agriculture.

The Australian Bureau of Statistics' latest Agricultural State Profile demonstrates the importance of reliable water supplies to farming businesses for Victoria. It shows that the number of farms in Victoria has dropped from 36,656 in 1997 to 32,463 in 2004, with the largest drop in 2002, the driest year in that period. Approximately 75% of water consumed for irrigation comes from the Murray-Darling Basin and based on a 'business as usual' scenario of greenhouse gas mitigation, evaporation of water from the Murray-Darling Basin could be as great as 45% by 2070.

The AGO's report on Risk and Vulnerability provides some assessment of the potential economic losses to the agriculture sector:

• drought reduction in pasture growth could cause an $8 billion loss in annual export earnings
• fruit and vegetable crop lost earnings of $2 billion annually
• perennial horticulture losses due to higher water demand and other costs to potentially reach $2 billion per annum
• annual broad-acre crops lost production in marginal areas worth as much as $8 billion

Indigenous peoples, the elderly and families on low-incomes are likely to struggle to compensate for the increasing costs of basic food commodities as crop yields diminish due to water-stress. Higher production costs will be reflected in both the market and local availability. This has lead to a growing concern that higher prices for fresh produce will force those on low incomes to purchase lower quality, processed foods that already contribute to health complaints such as childhood obesity and diabetes.[1]

See also: Health

Regional communities
Climate change will affect regional Australian communities unevenly. Some of the impacts on tourism and planning are detailed in other pages on this site.

The following areas are listed as most vulnerable by the Australian Greenhouse Office because they already exhibit economic or environmental stress; host climate sensitive industries, or are of recognised national significance:

• low lying coastal population and resort centres;
• tropical and sub-tropical population centres;
• alpine regions;
• centres with a high dependence on agricultural and/or eco-tourism activities;
• remote Indigenous communities (particularly in the far north of Australia); and
• areas of southern and western Australia facing acute water shortages and supply constraints.

Tropical areas
Tropical cyclones and severe storms are likely to increase in intensity as a result of climate change, affecting communities in tropical areas (ibid). This could put some of Australia's significant population and tourist centres like Cairns, Broome, Darwin and Townsville, as well as remote communities, at considerably increased risk. Indigenous communities in remote areas will be particularly affected due to existing economic, housing and health vulnerability.

Alpine regions
Alpine ecosystems are extremely vulnerable to future climate changes. This is due to their small geographical extent, high degree of sensitivity, relatively modest seasonal snow cover and depth, and high diversity of flora and fauna, many of which are already threatened. It is predicted that Alpine regions will experience an 18-66% reduction in snow cover by 2030, and a 39-96% reduction by 2070. Such outcomes will have a seriously adverse impact on Alpine regions and their communities, and will greatly increase the risk of fire in sensitive areas previously devoid of fire (ibid). Overall, decreased snow and rainfall and increased temperatures caused by climate change will leave very little opportunity for Alpine ecosystems to adapt (ibid).

Remote Indigenous communities
(particularly in the far north of Australia)
Indigenous communities, already the most marginalised in Australia, have few of the resources available to other communities to deal with the impacts of climate change. As such, they will be disproportionately affected by health impacts such as changing distribution of vector borne diseases including malaria and dengue fever, as well as increased intensity of extreme weather, and loss of culturally significant ecosystems such as the Kakadu coastal wetlands.

CSIRO Darwin held a conference on the impacts of climate change upon Indigenous communities and published the presentations from this conference at http://www.dar.csiro.au/sharingknowledge/workshop.html

Areas of southern and western Australia facing acute water shortages and supply constraints
The CSIRO has monitored trends in rainfall and found that in the north, trends have moved towards increasing rainfall over summer months in large parts of western, northern and central Australia from 1952 to 2002. In the south, long-recognised trends towards drier conditions have been observed for south-west Western Australia, and southern Australia as a whole (ibid). South West Western Australia has exprienced a 10-20% decrease in winter rainfall over the past 3 decades (http://www.greenhouse.gov.au/impacts/publications/risk-vulnerability.html).

The Western Australian Environment Department reports that:

• rainfall is predicted to decrease 11% over the next 50 years, which equates to a 31% reduction in run-off into dams
• a 12% drop in rainfall and a 40% drop in run off has already occurred between 1975 and 2003.

Adelaide's water supply will be one of the most vulnerable of any Australian city under future climate change scenarios. The state of South Australia is likely to experience an overall decrease in winter water runoff of up to 25% by the year 2070. This will lead to an associated decrease in soil moisture of up to 10%. Southern Australia is also extremely vulnerable to an increase in bushfires, because extreme fire danger is connected with periodic drought conditions, leading to drying of fuel, and extremely hot summer and autumn days. These conditions are expected to increase with global warming in southern Australia.