Adapt

Climate change increases the variability of temperature and rain patterns. In addition, a whole range of extreme events – such as floods, droughts and heat waves – and associated risks such as price volatility, pests and diseases become more likely.

Dairy farmers have already seen the impacts of climate change on their businesses:

• In Gippsland and northern Victoria, pasture growth patterns have changed and spring now starts about four weeks earlier.
• In the northern irrigation area, reduced water availability has favoured annual pastures over perennial pastures. Farmers are investigating pastures such as lucerne, which have deeper root systems and can tolerate longer periods of water deficiency.
• In response to more competitive land and water use in South Australia, as well as reduced availability and quality of water, some farmers are already making changes to their systems, while others are relocating.

Adapting and building resilience to a changing climate needs to take into account the unique economic, social and environmental pressures each dairy business faces. Consequently, the planning of a climate-ready dairy business requires an understanding future climate projections and their potential impact across the business. All practices and responses can then be evidence-based and context-specific.

While current climate change projections based on averages pose only a limited threat to many dairy regions, the main impact for most dairy farms will be through increased climate variability.

Extreme weather events such as flooding, bushfire, droughts, failed spring conditions, wet winters and wind storms will increase in frequency and intensity in the future.

Dryland dairy businesses that currently rely on summer pasture/crop growth may face difficulties into the future as warmer and drier climate scenarios are predicted to change the seasonal pattern of pasture production. Winter and early spring pasture growth rates are predicted to increase, but the length of the growing season is predicted to shorten.

Wealth, learning and formal education and availability of adaptation options are key factors influencing climate-related adaptive farm management.

Visit the Climate Change in Australia website to access site-specific information on climate projections.

Impacts on Cows

Cows have evolved a range of mechanisms to off-load heat, but problems can occur if temperatures and humidity remain high. Heat load accumulation can occur when hot nights do not allow animals to recover.

At temperatures above 25 degrees Celsius, a cow begins to feel uncomfortable, reducing their ability to produce milk and get in-calf. Their health and welfare may also be affected. The increase in metabolic activity associated with high milk yields has added to the heat stress dairy farmers must manage in their herds.

Of the European dairy breeds, Brown Swiss and Jersey are least vulnerable to heat stress, then Ayrshire and Guernseys, followed by the Holstein-Friesian.

More information on the impact on heat and climate change on cows is available here.

Impacts on pasture

The combination of increased atmospheric carbon dioxide concentrations, higher temperatures, lower rainfall and increased climate variability will challenge some aspects of the current dairy feedbase, while benefiting others.

The overall challenge remains producing (and sometimes preserving) home-grown forage of a suitable quality to match the feed requirements of the herd at a suitably low price to meet farm business requirements. In all cases, the scale of the response will depend on the scale of any climate changes.

Temperatures during winter will be warmer and there will be fewer frosts in some regions, so pasture growth rates are likely to increase over winter. This may influence other decisions associated with calving time, grazing management, fertiliser (especially nitrogen) timing and amount and cutting times for hay or silage.

Feed gaps are likely to be more frequent, so feed purchasing and/or forage conservation activities may become more important as part of total farm management.

Future warmer and drier climate scenarios will alter the balance between the productivity and persistence of perennial grasses to support livestock production systems (Cullen et al). Heat tolerance and rooting depth are key factors and will influence a farmer's choice of species.

Depending on their dairy region, the following are some of the general pasture impacts farmers might see as a result of climate change:

• Winters will be warmer with fewer frosts. Pasture growth rates could be higher in winter in southern dairy regions and using nitrogen fertiliser during winter may become more effective
• Summer will be hotter, beginning earlier and finishing later - potentially causing heat/moisture stress over summer, while shortening the peak of spring growth and delaying the start of autumn. Short rotation pasture systems and winter fodder crops may become more attractive than irrigating pasture over summer
• Increased temperatures may make C4 pasture species like paspalum, kikuyu, maize and forage sorghum more competitive at the expense of the nutritious C3 species like ryegrasses
• Irrigation requirements will increase with higher temperatures and lower rainfall. Irrigation availability is likely to decrease, magnifying the impact on pasture production.

The impact of climate scenarios will affect regions differently:

• Those regions that are currently hot and dry (such as Moree and Wagga Wagga, New South Wales) will remain so, but existing pasture types at these locations based on a mix of C3 and C4 species appears to be quite resilient to the changes in climate.
• In other regions, hotter and drier conditions are likely to challenge the productivity and persistence of current pasture species, particularly where the current species are near the edge of their adaptive range (such as perennial ryegrass-based pastures at Hamilton and Terang in south-west Victoria).
• In cool temperate sites, perennial ryegrass production will increase in warmer and drier scenarios and its benefits in ease of management are likely to see it continue to be widely used. However, as the climate becomes warmer and drier, deeper rooted options such as tall fescue and phalaris may be integrated into the systems.
• Overall, increasing numbers of hot and dry days will challenge the persistence shallow rooted perennial grasses such as ryegrass. This will tend to favour the summer dormant species such as phalaris, however the trade-off between the ease of management of ryegrass with the persistence benefits of phalaris is likely to be amplified in many regions of southern Australia.
• Kikuyu is very reliant on summer rainfall to grow, so its production is highly susceptible to rainfall decline. In addition, low winter production will limit its adoption as feed grown through this period is valued a lot higher by farmers.

Impacts on farm water supplies

Climate change projections indicate farm water supplies will decrease due to lower rainfall, higher evaporation, changes in seasonal patterns and more frequent and longer droughts. These factors generally cause run-off to be reduced at more than double the rate of rainfall reduction.

Farmers who rely on surface run-off for irrigation or dairy supplies could face more severe water shortages. However, run-off estimates are not always reliable because run-off depends on timing and intensity of rainfall as well as rainfall amount.

If there is less rainfall and run-off, then reductions in the reliability of supply will vary but they are likely to be greatest where surface water use is already high and where climate change is predicted to have the largest impact on water availability. In the Murray-Darling Basin this would be the Murray, Goulburn-Broken, Campaspe, Loddon-Avoca and Wimmera regions.

By 2030 predictions, the availability of surface water in the Murray-Darling Basin will reduce by an average of 11%, 9% in the north of the Basin and 13% in the south.

Impacts on biosecurity

Future climate changes will influence the spread of livestock and pasture pests, disease and weeds. See the Biosecurity page for more on managing this risk.

Some adaptation steps that dairy farmers are taking include:

• Increasing stock shade and shelter for extreme conditions
• Water saving and recycling in the dairy shed
• crops to fill the feed gap
• Carrying larger fodder reserves
• Infrastructure for feeding cows – sheds or pads
• Upgrading on-farm water infrastructure
• Fans and sprinklers in sheds and yards
• Business management – planning for income variability
• Accessing long-range weather forecasts
• Watching and planning for global market conditions

Dairy Australia and its partners have been very active in supporting research and development into adaptation options and strategies to assist the dairy industry to adapt to climate challenges.

The Dairy Businesses for Future Climates (DBFC) project has undertaken four dairy case studies across Australia to consider what climate conditions will occur in dairy regions into the future and explore what farm systems may best suit those conditions.

Climate risk is an emerging requirement of corporate governance and has the potential to impact access to capital and markets.

Key messages from the experts on managing for climate risk include:

• The world is currently living through unprecedented times of change (technological, society, economic and climate).
• Global action on climate change (Paris Agreement and Task Force on Climate Related Disclosures) will have implications for sustainability and emissions reductions in the short-term. Focus will be on a zero carbon economy, not a low carbon economy transition.
• Management of climate risk will increasingly be an emerging requirement of corporate governance, access to capital and access to markets for the dairy sector. Consequently, climate risk needs to be considered like any other material risk to companies/enterprises.
• Corporates are more influential in driving the agenda with respect to climate risk than governments
• Climate risk includes both exposure to climate change (acute and chronic physical impacts), as well as the transitional costs (financial and legal requirements) to a zero carbon economy.
• Directors have a duty to consider climate risk. Fiduciary duties report notes that the risk has to only be foreseeable, not probable, for directors to have a responsibility to act.
• A company needs to know how to mitigate against the physical and transitional climate shocks.
• The 2040 scenarios for physical changes to climate are happening now in some regions. Adaptation is not an optional add-on for businesses – it should be a fundamental part of business planning. Adaptation is about changing what currently happens (tactics/strategies) to get the desired outcome (values/result).

The original legal advice on fiduciary duties of climate change by Noel Huntly is at Legal Opinion: Fiduciary Duties & Climate Change (2016). It emphasises that as the economic and environmental implications of climate change intersect, company directors are legally empowered to elevate climate-related risks and opportunities to the forefront of corporate strategy.

Dairy farming is already about implementing the best possible business management strategies to ensure the production system can be adjusted as each season progresses. This will not change, but the challenge may be greater with increased climate variability and input and milk price volatility. Consequently, some current business planning and management strategies may need revision.

At the strategic level, dairy farmers will need to determine which (if any) of the climate change issues should be the subject of immediate management action.

• Those which require a watching brief but no current action
• Those which can be dismissed from current planning or action.

The Taskforce for Climate-related Financial Disclosures (TFCD) is a good framework for dairy farmers considering adopting climate risk considerations across their business in the meantime.

More information is available on the TFCD and dairy fact sheet.

Operating and transitioning dairy businesses into the future will rely on the skills and knowledge of managers and operators, as well as their broader social networks. Engaging with peers, professional services and industry-based organisations will assist dairy business managers in accessing resources, participating in learning and mentoring opportunities and finding new ways to manage a range of risks in a networked environment.

For more information read the report Supporting dairy business managers to manage for future climates. This report provides a comprehensive outline of the support needs of dairy business managers in the context of future climate challenges and operating in a variable environment. It highlights the critical role of policy, government and the dairy industry in providing ongoing support structures, processes and resources to enhance the capacity of dairy business managers in responding to socio-environmental change and continuing dairying into the future.