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Agriculture covers around 70% of the UK’s total land area. Over half a million people are employed in UK agriculture, which contributes £7.1 billion to the UK economy.

Many of the challenges facing the UK agriculture sector can be linked to socio-economic, environmental and technological trends and issues – with climate change being an exacerbating factor, rather than necessarily the driving force of change. Key challenges include food security (the ability to ensure all citizens have access to affordable, nutritious food), rising demand for food due to population growth, changing consumer preferences and compliance with regulations. Increasing energy prices may also present  a significant challenge, together with international pressures and market competition.

UK agriculture could be significantly affected by climate change. Rising temperatures and changing rainfall patterns, changes in sunshine levels and in concentrations of atmospheric carbon dioxide (CO2), and increasing frequency of weather events currently considered extreme would all have an impact on operations, productivity and the range of products offered by the sector.

Climate change could also affect global food production and have knock-on effects for UK agriculture and the food industry. Climate change is projected to result in changes in temperature, rainfall patterns and sea levels, as detailed in the UK Climate Projections (UKCP09) analysis. Although most of the impacts on the agriculture sector may be negative, potentially valuable new opportunities may also arise that can benefit existing agricultural activities and encourage farm diversification.

Warmer temperatures and higher concentrations of CO2 in the atmosphere would lead to higher yields of many crops currently grown in the UK. These benefits will not happen, however, if rising temperatures and lower summer rainfall result in increased heat stress to crops and significant decreases in soil moisture. In some cases, faster growth rates may reduce crop quality.

Overall, yields of crops such as wheat and sugar beet are projected to rise. Grass yields may also increase, although in some parts of England and Wales dry conditions may limit this. In Scotland and Northern Ireland, where water stress may be less of a problem, there is the potential for more significant increases in grass yields, which may prove beneficial for livestock and dairy producers.

There could also be opportunities to introduce new crops or to expand existing crops that are currently only grown in small quantities, especially in the south, such as blueberries and maize, for example, as well as new industrial, energy and pharmaceutical crops.

However, increases in rainfall intensity or the frequency of intense storms could increase the risk of soil erosion throughout the UK, although the implications for crop yields are unclear.

Positive effects

• Increase in wheat yields: between 40% and 140% by the 2050s, assuming other factors affecting growth are not limiting (baseline: 1961-1990). Wheat yields are expected to start increasing from 2020s.

• Increase in sugar beet yields: between 20% and 70% by the 2050s, assuming other factors affecting growth are not limiting (baseline: 1961-1990)

• Increase in grass yields: between 20% and 50% by the 2050s, assuming other factors affecting growth are not limiting (baseline: 1970s-1990s)

Negative effects

• High-quality horticultural and arable land likely to be flooded at least once every 3 years: 35,000 ha by the 2020s, 75,000 ha by the 2050s and 130,000 ha by the 2080s (current figure: about 30,000 ha).

• By the 2050s, southern, eastern and central England may have water needs greater than those currently experienced anywhere in the UK. Rising agricultural water demand due to a drier climate, coupled with rising water demand from other sectors (e.g. energy and water companies), could coincide with less water being available for agriculture. 

•  Changes in the frequency of intense rainfall events, particularly following periods of dry weather, could contribute to increased nutrient runoff from agricultural land, which may affect local water quality.  As well as harming biodiversity and ecosystems, this may affect the quality of water abstracted downstream, having cost implications for water treatment and potentially affecting the health of those using private water supplies. 

Livestock Issues

Pigs and poultry may be particularly vulnerable to heat stress, with poultry suffering higher mortality rates and producing fewer eggs, while transportation of animals during heatwaves may pose major risks to their health and welfare. Heat stress is projected to begin affecting dairy production by the 2050s. By the 2080s, the impact may become significant for farmers operating on low margins and for regional economies reliant on exporting dairy products. 

By extending the growing season in upland areas, however, warmer temperatures may result in more winter grazing and forage, assuming access is not limited due to wet conditions. Milder winters may reduce feed and bedding costs by cutting the length of time livestock need to be housed. If summers became hotter and drier, however, this may result in insufficient forage for grazing animals, particularly in the south of the UK.

The evidence that climate change will increase crop pests and diseases is weak. However, the interactions between crops, pests and pathogen are complex and currently poorly understood in the context of climate change. It is also difficult to analyse the future level of risk as agricultural pests and diseases are managed and controlled in a variety of ways.

For example, although climate has also been linked to the spread of some strains of Bluetongue virus, its emergence in northern Europe is not explained entirely by climate change but by a complex combination of drivers such as an increase in international transport.

As hot dry weather is unfavourable to most sheep parasites, the numbers of roundworms, blowflies and ticks may decrease in some parts of the UK.

The Challenge of Adaptation

Agriculture is a particularly diverse industry, incorporating international agri-businesses and family farms and ranging from outdoor crop cultivation to indoor livestock rearing. The ability to adapt to climate change varies accordingly across the sector.

Many horticultural businesses, for example, are highly innovative and can adapt quickly, while some sub-sectors are less able to adapt or may be able to adapt to some changes but not to others.

Adding to the challenge of adaptation is the fact that considerable uncertainty surrounds (i) the way different climate impacts on this sector may interact with each other and (ii) the socio-economic changes that will have a major influence on the continued evolution of UK agriculture. Specific knowledge gaps identified by the CCRA include:

The potential impact of climate change on agricultural pests and diseases.

The effects of climate change and climate extremes on water available for new and existing crops, especially in areas affected by sea level rise and coastal flooding.

The effects of climate change on animal health and welfare, and particularly the effects of heatwaves and droughts.

The ability of rural communities to adapt to the effects of climate change on their lives and livelihoods.

Full report

http://randd.defra.gov.uk/Document.aspx?Document=CCRAfortheAgricultureSector.pdf

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