The world’s climate is changing and we need to adapt, both to changes that have already happened, and those that will be faced in the future. Agriculture makes a significant contribution to climate change, and is estimated to account for 10-12% of global greenhouse gas (GHG) emissions.

Within the UK, recent policy measures such as the Climate Change Act (2008) have set ambitious targets for emission reductions in the UK and, as with other sectors, cost-effective abatement measures for agriculture need to be identified. Within this context, the Organic Research Centre is investigating the potential contribution that organic agriculture can make toward climate change mitigation and adaptation, and providing evidence to policy makers, researchers and the general public, on the benefits that organic systems provide.

How agriculture influences climate change

Agriculture influences climate change in a number of ways, although the extent of this contribution depends very much on where the boundaries of the assessment are drawn. The main contributors are as follows:

  • Land use change: with an increasing demand for cheap food and growing numbers of livestock, land-use change has become the main issue for agriculture and climate change. The main cause for concern is deforestation and burning in the tropics, most of which is associated with land clearance for growing energy intensive crops such as soya and maize. The total contribution from land use change is responsible for nearly 50% of total GHG emissions from agricultural production. For more information on this issue see UN Reducing Emissions from Deforestation and Forest Degradation Programme (REDD).
  • Fertiliser application: fertiliser application is the single largest source of direct nitrous oxide (N2O) from agricultural soils. N2O is a greenhouse gas 298 times more damaging than CO2 in terms of its global warming potential. As a result this source accounts for over 50% of direct emissions from agriculture in the UK and 16% of global greenhouse gases from agricultural production. For more information on this gas and measures being taken to reduce its impact see Air Pollution Information System nitrous oxide pages.
  • Enteric fermentation: when livestock digest feed and forage, methanogenic mircorganisms within the digestive tract produce methane (CH4), a substance with 25 times the global warming potential of CO2. Methane accounts for over 27% of agriculture’s GHG contribution globally, and over 40% of emissions from agriculture in the UK – cattle, sheep and goats are the primary ruminant livestock in the UK and together emit more than 75 per cent of the methane released. For more information on this greenhouse gas and agriculture’s contribution see Chapter 8 of the Intergovernmental Panel on Climate Change (IPCC) 2007 report (external PDF 968KB) and the Farming Futures (external PDF 206KB) website.
  • Fossil energy use: The intensive field operations that modern agriculture systems increasingly rely on also contribute significantly to global warming, both through the diesel required to fuel tractors, combine harvesters and other items and through the manufacturing process. The amount of fossil fuel required to produce inorganic fertiliser creates a huge carbon footprint – this source alone accounts for more than 50% of the fossil fuel energy used within agriculture globally. For more information see Farming Futures Energy (external PDF 1.43MB) use on farms guide.

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How organic farming can contribute to reducing climate change impacts

Organic farming systems can help to mitigate and adapt to climate change in a number of ways.

Use of nitrogen fixing legumes and manures in place of manufactured fertiliser

In organic agriculture, plant nitrogen requirements are supplied primarily by using nitrogen- fixing leguminous plants and the application of manure and compost. This avoids the greenhouse gases associated with the manufacture of inorganic nitrogen fertiliser and helps to avoid organic matter losses associated with inorganic nitrogen use. Organic agriculture also has lower N2O emissions from nitrogen application, due to lower overall nitrogen input per ha than in conventional agriculture and greater care with the timing of manure applications to reduce nitrogen losses.

The Organic Research Centre’s Legume LINK (PDF 13KB) project is currently investigating how mixtures of legume and grass species can be tailored to optimize the amount of nitrogen that is fixed, transfer the nitrogen to the subsequent crop with the appropriate timing, as well as perform reliably under local environmental conditions.

Increased greenhouse gas efficiency through mixed farming systems

Organic principles specify that farming systems should be self-sufficient, as far as possible, with regard to animal feed, fertilisers and manures. This approach of promoting a self-contained farm organism helps avoid the problem of ‘importing’ hectares by purchasing feeds from other regions for the purpose of increasing livestock yields and stocking rates, often seen in non-organic systems. Moreover, conventional stockless arable farms depend on the input of synthetic nitrogen fertilizers, while stockpiled manure and slurry on livestock farms can create additional emissions and other environmental problems- organic farms mitigate such problems by on-farm or cooperative use of farmyard manure between crop and livestock operations. However, specialised organic farms also exist and particular care is required on these holdings to reduce potential negative climate change impacts.

Less fossil energy use

Less fossil energy is used within organic systems than non-organic systems, on a per hectare and, in most cases, on a per unit of food produced basis. The lower energy use on organic farms is largely because energy inputs for industrial manufacture of fertilizers and pesticides are avoided. Ca.1% of global fossil energy consumption is used for chemical nitrogen fertilizer production, which is not used by organic farmers and therefore organic agriculture does not contribute to these emissions.

Carbon sequestration.

Maintaining and increasing soil organic carbon in agricultural systems has been identified as the single mitigation option with the greatest potential to reduce agriculture’s climate change impacts. Organic agriculture has a significant contribution to make in this respect: practices that are commonly used on organic farms (use of organic fertilizers, fertility building leys with legumes and cover crops) further the production of soil organic matter which removes CO2 from the atmosphere and stores the carbon as biomass and soil organic carbon in the soil, reducing its release back into the atmosphere. A recent report (external PDF 223KB) completed by the Organic Research Centre, on behalf of Organic Centre Wales for the Welsh Government, reviewed the evidence of organic farming’s contribution to soil carbon sequestration.


The production of livestock or food crops on land that also grows trees for timber, firewood, or other tree products (agro-forestry) may also increase soil carbon sequestration; the standing stock of carbon above ground is usually higher than the equivalent land use without trees. The Organic Research Centre is currently exploring the benefits that agro-forestry can provide in this area. See here for more information of the Research Centre’s work in this area.

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What ORC is doing

Greenhouse Gas Action Plan (England)

In April 2011 the English agriculture industry published its voluntary action plan for reducing greenhouse gases. The Greenhouse Gas Action Plan (GHGAP) (PDF 519KB) sets out how the agricultural industry in England is responding to the challenge of climate change. It contains a commitment to reducing agricultural greenhouse gas emissions by three million tonnes of CO2 equivalent per year from 2018-2022.

The Action Plan aims to meet this target without compromising domestic production, as it is too simple a solution to produce less and import more. Instead the Action Plan focuses on how farmers, across all sectors and farming systems, can become more efficient to help reduce greenhouse gas emissions and make cost savings per unit of production.

The Organic Research Centre’s involvement as a member of the steering group for the Action Plan includes recommending organic practices such as use of fertility building leys containing legumes in place of manufactured fertiliser inputs and promotion of livestock health and longevity, as well as providing evidence of their impacts in terms of reducing greenhouse gas emissions.

International Round Table for Organic Agriculture and Climate Change (RTOACC)

The Roundtable on Organic Agriculture and Climate Change (RTOACC) is a multi-stakeholder initiative. It was founded on December 16, 2009 in Copenhagen, at the United Nations Climate Change Conference. RTOACC brings together stakeholders and partners along the organic food production chain. The activities are funded by the UN Food and Agriculture Organisation (FAO).

The Round Table aims to promote the potential of organic farming to mitigate and adapt to climate change, and build awareness of the advantage of organic farming systems in this context. The Round Table also advises the international community on organic agriculture and climate change issues, to help initiate changes in policy and wider support of organic agriculture and advise the development of climate-related provisions in international standards.

The Round Table also aims to support management practices and standard development issues that look at improving organic standards from a climate change perspective.

The Organic Research Centre has been involved with the development of the Round Table since 2010 and are helping to build an evidence base for the benefits of organic agriculture with regard to the climate change.

The next meeting of the Round Table is scheduled to take place at the Organic Research Centre’s Elm Farm venue on 29th February 2012.

Organic Agriculture and Climate Change Research

The Greenhouse Gas Platform: Data Management and Modelling project
The Organic Research Centre is working together with 16 organisations as part of the Agricultural Greenhouse Gas Research Platform, a Defra and devolved administration funded project which aims to improve the accuracy of the UK’s agricultural greenhouse gas inventory.The Organic Research Centre’s involvement in this project is focussed on the development of a greenhouse gas inventory reporting methodology, a review of UK industry and Government-level farm practice data, to determine its potential for improving the accuracy of the current reporting, and knowledge exchange with the UK industry. More information on the Greenhouse Gas Platform can be found on the Platform website at

Assessment of the climate change mitigation potential of organic farming systems (PhD thesis)
ORC’s Sustainability Researcher Laurence Smith is undertaking this PhD thesis, supported by the Organic Research Centre and supervised by the Cranfield School of Applied Sciences, with the aim of assessing the environmental and economic implications of a large scale conversion to organic farming within England and Wales.

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Latest news and developments

Seminar on organic agriculture and climate change in the European Parliament: presentations now available

On October 18, 2011, the seminar “Agriculture in Times of Climate Change – Organic Farming Approaches to Face the Challenge” took place in Brussels, organized by the EU Group of the International Federation of Organic Agriculture Movement, Bio Austria, MEP Elisabeth Köstinger and the Round Table on Organic Agriculture and Climate Change (RTOACC). Following the seminar, RTOACC held a series of sessions to exchange the last scientific data and devise strategy for future collaboration and action. RTOACC also held meetings with members of the European Commission from the Directorates-General for Agriculture, Climate and Development and Cooperation about the contribution organic agriculture can play in combating climate change. Presentations from the seminar are now available.


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