Committee on Climate Change

(1)    On-farm abatement options

Best practices and technology
The Committee’s analysis in the December 2008 report suggested that emissions could be reduced through:

• Improving the efficiency with which fertiliser is applied, to minimise the excess that is converted to N₂O;
• Improving the efficiency with which animals convert the carbon content of their feed and grazing into meat, rather than methane;
• Capturing methane from manures and farm wastes and using anaerobic digestion to produce energy from it.

The Committee noted a number of uncertainties in its analysis given the earlier stage of the evidence base for agriculture but suggested it was robust enough to recommend that agriculture emissions form part of broader strategy to meet carbon budgets.

The Government has since committed (in the Low Carbon Transition Plan) to a target of reducing emissions by 3 MtCO₂e in England in 2020 (compared to UK non-CO₂ emissions of 44 MtCO₂e in 2008). A similar level of ambition in the devolved administrations would deliver an additional 1.5 MtCO₂e for a total of 4.5 MtCO₂e in abatement across the UK by 2020. The target for England will be delivered through voluntary action by the industry (described in the Industry Greenhouse Gas Action Plan) and further development of the evidence base (e.g. an improved agriculture GHG inventory).

In its 2010 Progress Report to Parliament (June 2010) and 2010 Fourth Budget Report (December 2010), the Committee presented new analysis which suggests that emissions reductions above 4.5 MtCO₂e may be possible. Analysis by the Scottish Agricultural College (SAC) finds a range of 8.6 to 18.9 MtCO₂e of abatement potential from soils and livestock measures at a cost less than £70/tCO₂e (the projected carbon price for 2030). The range reflects uncertainties relating to baseline farming conditions against which the measures are applied, the technical effectiveness of abatement measures, and whether some measures might be permitted under future regulatory regimes. Many of the measures entail more efficient use of resources and as such they can potentially result in cost savings for farmers.

Agriculture MACC maximum technical potential, pessimistic case (2022)

Agriculture MACC maximum technical potential, optimistic case (2022)


Additional abatement measures, including more radical options
Additional management and technological options could provide further abatement over time but would require research effort and funding. These options would also be subject to regulatory barriers, public acceptability and trade-offs between low-carbon and other objectives from the farming sector (e.g. animal welfare, biodiversity). Additional measures could include:

Wider measures to improve soil management (e.g. residue and waste management to improve soil structure and sequester carbon)
Improved cattle health through reductions in endemic disease
Alternative dietary energy sources for cattle and sheep, which could reduce methane production and/or improve yields
Other scales/types of anaerobic digestion systems
Increase use of nitrogen efficient crop varieties, including use of more controversial technologies such as genetically-modified organisms
Alternative production systems (e.g. mixed farming)

Reducing on-farm CO₂ emissions

Agriculture is also responsible for around 4 MtCO₂ emissions arising from the use of machinery (e.g. tractors) and consumption of fuel in farm buildings. Preliminary analysis by Defra suggests there is cost-effective opportunity to reduce on-farm CO₂ emissions through use of efficient engine technology and alternative vehicle fuels as well as use of high-efficiency and biomass boilers.

(2)    Behavioural change
The Committee’s analysis on reducing emissions from agriculture has focused on changing farming practices and using new technologies as they relate to crops, soils and livestock. In its Fourth Budget Report, the Committee suggests that there are opportunities to reduce emissions through changes in consumer behaviour via reduction in food waste or a changed mix of diets, with reduced consumption of carbon-intensive foods.

Reducing food waste

Currently 16 million tonnes (MT) of food and drink is wasted in the UK on an annual basis. Of this 16 MT, 8.3 MT is wasted by households. Some household food waste is unavoidable (e.g. eggshells and banana peels) but around 5.3 MT is food and drink waste that could have been avoided (e.g. through better planning and preparation). Avoidable food waste costs the UK £12 billion per year, equivalent to around £480 per household.

Total emissions associated with this avoidable food waste are estimated to be 20 MtCO₂e on a consumption basis, which includes emission contributions from the relevant elements of the food and drink sector including agriculture, manufacture, packaging, distribution, retail, transport to the home, storage and preparation in the home and waste treatment and disposal (excluding emissions associated with food and drink exports). UK agriculture emissions account for 6.5 MtCO₂e of the 20 MtCO₂e figure.

Analysis by the Waste Reduction Action Programme (WRAP) suggests that up to half of this food waste could be reduced through simple measures, including information-provision and engagement with retailers, brands, local authorities and households to encourage reduced waste. This is associated with emissions of 3.2 MtCO₂e from farming, although it is difficult to estimate the likely impact of food waste reduction measures on agricultural emissions. For example, better planning, storage, and packaging may reduce household purchase of food, but it is not clear whether this would result in a corresponding reduction in agricultural production (e.g. the food and drink sector could export more products). However, the fact that this opportunity is available at negative cost (i.e. saves households money) suggests that policy effort in this area is worthwhile.

Changed diets
In its 2008 Report, the Committee presented evidence, based on life-cycle assessment of GHG emissions arising from food products, which showed the relatively higher carbon intensity of red meat products. This reflects the inefficiency of sheep and cows at processing food and emissions arising from their digestive processes.

The Committee suggested that rebalancing diets towards less emissions-intensive food could therefore reduce emissions and form part of a strategy to meet the 2050 emission reduction target. This would be subject to resolving a number of issues, including the potential impact of changes in food consumption patterns on land use and related emissions, which are important both within the UK and abroad. For example, cattle and sheep convert grass (which cannot be digested by other animals) into food and use land (grassland) that in some cases cannot be used for other purposes (e.g. for crop production). Conversely, pigs and poultry consume feed crops, which compete more directly with land to support crops eaten directly by people. Changing diets may require increased production of substitute goods (e.g. fruits, vegetables and legumes) and as a result lead to land-use change and related emissions.

In its Fourth Budget Report, the Committee presents new analysis conducted by Cranfield University that examines the emissions and land use impacts of dietary change away from livestock products (beef, sheepmeat, dairy pigs and poultry). The study finds that rebalancing diets could not only reduce UK GHG emissions (by up to 40%) but could also free up land, both with the UK and abroad, which could be used for other purposes (e.g. extensification of livestock production, increased food production, bioenergy production, forestry, etc.).

In general, there are likely to be health benefits from reducing excessive consumption of livestock intake but further work is required to determine the health impacts of a lower-carbon diet.

Cutting emissions by reducing food waste and rebalancing diets raises broader questions about production- versus consumption-based emissions. For example, food products are both imported and exported, so any change in UK food consumption may not impact UK food production and emissions. This is an issue given the accounting framework under the Climate Change Act, which is based on production rather than consumption emissions. It raises the possibility that reductions in food waste and changed diets would not contribute to meeting carbon budgets, notwithstanding any global benefits that this would give rise to. The issue around production- versus consumption-based accounting approaches is one which the Committee will give future consideration.