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How do we adapt agriculture to climate change?


This unit looks at how industrial agriculture is one of the anthropogenic causes of climate change. It goes on to consider what adaptations must be adopted in order to mitigate its impact on climate change. The concept of food security is introduced and its link to climate change explored. Finally, the notion of adapting agriculture through the way we design and live in cities is presented.

Unit authored by Alissa Pemberton

Learning outcomes

By the end of this unit you should:

  • have developed an understanding of the relationship between industrial agriculture and climate change;

  • understand how fundamental structural adjustments in agricultural policy and a shift in farming methods will help mitigate climate change;

  • be able to think of cities in terms of their food needs and understand how urban agriculture can play a part in making sustainable cities;

  • have developed systemic learning of the wider, systemic picture in which climate change is happening.

1 Greenhouse gas emissions from agriculture

1.1 Greenhouse gases

The relationship between agriculture and climate change is a complex one.

Agriculture is part of a wider ‘food system’, which includes the transport and distribution of food, its processing and cooking and dealing with food-related waste resources. Our food system not only produces climate-changing gases; it in turn is influenced by them.

Agriculture is just one part of the food system that generates the greenhouse gas emissions that contribute to climate change.

Agriculture produces three main types of gas emission that cause climate change: methane, nitrous oxide and carbon dioxide.

  • Methane has around 20 times the greenhouse effect of carbon dioxide and is released by natural livestock emissions and manure.

  • Nitrous oxide has around 310 times the greenhouse effect of carbon dioxide and is released from the production and use of fertiliser (including from muck spreading) and soil disturbance.

  • Carbon dioxide is released by burning fossil fuels (e.g. fuel in tractors, farm vehicles, machinery and the production of agricultural chemicals), changes in land use and land management.

It is estimated that food-related activity (not just agriculture but all parts of the food chain) could contribute up to 32 per cent of global greenhouse gas emissions.

1.2 Livestock

There are some types of agriculture that contribute disproportionately high greenhouse gas emissions. Industrial livestock farming is one of them. Read the report, Livestock's Long Shadow, from the United Nations Food and Agriculture Organisation. It describes how industrialised livestock farming contributes to climate change through:

  • the physical emissions of carbon dioxide and methane from cattle

  • the clearance of forest for production of grain crops for livestock feed

  • the vast processing, refrigeration and transportation networks for meat products

  • the environmental toxicity of animal wastes from industrial livestock farms.

Conversely, extensive livestock rearing has the ability to lock up carbon in the soil of grasslands and is therefore a way to mitigate agricultural-related greenhouse gases.

The Soil Association suggests that the waste from sheep and cattle grazing on grasslands does not cause pollution as it is not concentrated and degrades naturally. Grazing animals are also converting something that humans can't eat (grass) into something we can eat (meat and dairy products). Also, importantly, grazing animals aren't consuming grain (which uses nitrogen fertilizer which in turn produces large amounts of highly damaging nitrous oxide emissions).

Meat and dairy products from grass-fed animals contain more beneficial nutrients and healthier fat than grain-fed animals. Grazing animals also help to preserve some of the most beautiful and highly valued landscapes in Britain – almost all our national parks and many nature reserves are maintained by grazing sheep and cattle. Grazing animals are protecting some of the most significant carbon stores on the planet: permanent grassland and heather moorland. We should view these areas as we do rainforests in terms of their ability to store carbon. If grasslands are no longer grazed and are ploughed up, they will release carbon into the atmosphere.

1.3 Glasshouse fruit and vegetables

Glasshouse fruit and vegetables also contribute greatly to the greenhouse gases released by the agricultural sector and this is an increasing trend caused by consumer demand for out-of-season, fragile and exotic fruits and vegetables. Many commercial glasshouses are heated with gas, sometimes artificially lit and they use high volumes of water. Their footprint also reduces the amount of land that could have a function in sequestering carbon. Add air freighting into the equation and the greenhouse gas emissions rocket. This is explained in more detail in the report from the Food Climate Research Network (2008), Cooking up a Storm: Food, Greenhouse Gas Emissions and our Changing Climate.

However, glasshouse growing is a complex issue and new developments are being made that use renewable energy technologies, reduce pesticide use through biological controls and cut water use – all helping to reduce greenhouse gases. (For further information visit the British Tomato Growers Association's website.)

2 How will agriculture be affected by climate change?

A changing climate will affect what we can grow, where we can grow it, how it is distributed and consumed, and who will be at risk of hunger.

In the industrial agricultural system, it takes 10 calories of fossil fuel to produce each calorie of food. This is clearly unsustainable and means that everything we eat that is produced using this system is contributing to climate change.

As a result of climate change, the UK is likely to experience:

  • increasingly warmer weather: the average annual temperature in the UK is expected to rise by between 1°C and 5°C by the end of the 21st century

  • warmer, wetter winters

  • hotter, drier summers

  • more summer droughts

  • more extreme weather events such as high summer temperatures and more winter storms

  • fewer frosts and cold winter spells

  • sea level rise: potentially by up to 80cms on parts of the UK coast during this century.

Farming Futures have produced a factsheet, What is climate change and how will it affect agriculture?

All these changes will have a drastic and, in places, an irreversible effect on agriculture. Cultivable land will be lost to sea level rises and soils will be degraded due to salination.

Extreme weather conditions will encourage more crop pests, which will produce increased pollution through more pesticide use. Top soil, our most precious resource, will disappear from deforestation, floods, landslides and droughts. These factors will result in the disappearance of farming livelihoods and lead to widespread food insecurity all over the globe. Rich countries will not be immune to this.

Climate change is already affecting agricultural communities all over the world. One of the charities working with many of them to implement practical and sustainable solutions is Practical Action. Listen to Hilary Warbuton from Practical Action speak at the Hunger and Climate Change conference in 2009.

Hunger and Climate Change conference 2009

The impact of agriculture on climate change will be accelerated by the reduction in the availability and price of fossil fuels. Unless the transition to lower carbon forms of agriculture (and in the wider food system) is well planned for, we will see more countries experiencing food crisis and continued food insecurity as shown in this report, Fuelling a Food Crisis, from the Leader of the Green Party, Caroline Lucas.

3 How will climate change affect food security?

3.1 What is food security and food sovereignty?

Food security is defined by the UN Food and Agriculture Organisation as ‘a condition in which all people, at all times, have physical and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life’. Details can be found on the Ryerson Centre for Food Security website.

Food sovereignty is a people’s, country’s or state’s right, rather than the right of transnational corporations, to define and control their own agricultural policies. Trade liberalisation policies prioritise international trade rather than food for people. They, therefore, contribute to climate change by perpetuating a fossil fuel energy intensive globalised food system. For examples visit the website of La Via Campesina the International Peasant Movement.

3.2 The impact of climate change on industrial agriculture

Almost one billion people in the world are hungry today. By 2050 our food systems will have to feed 50 per cent more people than they do today.

We can see then, that the overall impact of climate change on food security will be a consequence, not just of biophysical climatic changes, but of the social, economic, institutional, demographic and technological responses (or non-responses) to the challenge that climate change poses.

Food security is undermined by lack of action or the wrong kind of action in these spheres. It is also exacerbated by the following factors:

  • fossil fuel depletion

  • corporate control of genetic diversity, seeds and natural resources

  • displacement of indigenous people

  • soil degradation

  • water scarcity

  • increasing population

  • increasing urbanisation

  • intensive livestock farming

  • competition for land and resources

  • super farms and monoculture

  • poor planning of urban areas

  • just-in-time distribution

  • supermarket domination

  • geopolitics and war.

If we take our ‘just-in-time’ food distribution system, we can see that it takes only a minor shock to almost bring our food system to a halt. In the UK in 2000, road hauliers’ protests at increasing fuel costs led to a blockade of fuel depots across the country and brought the food distribution system to a standstill. Supermarket bosses told government ministers that shelves could be bare within three days. Considering 80 per cent of our food is purchased through supermarkets, this is a sobering example.

For further information see the report Nine Meals from Anarchy by Andrew Simms of the New Economics Foundation, 2008. And the UK government’s 2009 report, Securing Food Supplies up to 2050: The Challenges for the UK.

4 How can we adapt our food systems to mitigate these effects?

4.1 Developing a resilient food system

In order to increase our food security and reclaim our food sovereignty, a systemic and structural change must take place in how we plan our food systems. This will require a radical transformation of farming methods and reconstruction of more regionalised food processing and distribution networks.

It is not about aiming for complete self-sufficiency, however, but rather aiming for a way to develop a resilient food system that can respond positively to global shocks.

Work is already being done by individuals and communities on how to bring about this change despite the government’s insistence on continuing to promote policies that prop up trade liberalisation and the global market.

Activity 1

Read the following resources:

‘Can Britain Feed Itself’? by Simon Fairlie (2007). You can find it at Transition Culture.

The Soil Association’s plan for climate-friendly food and farming.

Also read examples of different approaches taking place in transition towns:

Can Totnes Feed Itself?, an article on the website of Transition Town Totnes.

Food Availability in Stroud District (2008); available from Stroud District Community Websites.

In 2006 I started to look at this issue in Milton Keynes, though at the time there was not the sense of urgency around climate change and peak oil. The emerging local food movement that was identified in my report has yet to really flourish in Milton Keynes though some progress has been made in getting the importance of local food planning into the Council's Core Strategy planning document, challenging the dominance of the supermarkets and setting up an urban farming demonstration project, which is supplying some of the city's restaurants with locally grown salads. There is still much to do and it would be useful to apply some of the more recent food planning frameworks to Milton Keynes.

See my report, Food MK: Using Food to Build Communities in Milton Keynes, by Alissa Pemberton published by Food Train in 2006.

4.2 The need for structural change

Systemic changes in where we live, how we live on the land, and our patterns of settlement will need to change radically. We will need to work towards the principle of ensuring that where possible our staple foods are produced close to where they are consumed in order to reduce food transport and support food security.

Many land reformers promote the idea of re-ruralisation; in other words, re-populating the countryside with low impact, localised agricultural communities. At present our planning system does not support this kind of development, though the government has many strategies around what it calls ‘sustainable communities’.

There will need to be more small farms, more mixed farming and family farms alongside producer cooperatives, larger farms and some imports. Where food is imported it must be only if it cannot be produced internally, and it must be traded fairly to avoid the so-called ‘food swaps’ where governments seek to raise taxes by importing similar amounts of foods to those they are exporting.

There will need to be a massive recruitment drive and re-skilling for low carbon farming. Many more people will need to be involved in food production, replacing the fossil fuel driven machinery that has replaced human energy. This is not to advocate a return to solely human labour. On-farm production of renewable energy will be vitally important. Farms will need to produce energy as well as food – not instead of.

Much of this must come about alongside a change in diet and tastes towards more plant-based foods that are less processed. We will have to eat less meat, and the meat we eat will need to be reared outdoors on extensive pasture systems. We will also have to drastically reduce the fossil fuel intensive production of cereals in the UK.

Farming methods will need to adapt and organic farming will need to be the minimum. Permaculture and agroforestry will have to play a much greater role in achieving multiple functions from land. So, as well as producing food, land must produce fuel, wildlife habitats and sustainable livelihoods.

The following resources present a positive vision for feeding the world, well within ecological limits:

  • Podcast by Patrick Holden, Soil Association Director

  • Article by Colin Tudge: Can Organic Farming Feed the World?

  • Video: A Forest Garden Year, Agroforestry Research Trust UK

  • Video: Permaculture Forest Garden at Schumacher College

  • Video: Farm for the Future, BBC2, 2009

  • Report by Practical Action: Biodiverse Agriculture for a Changing Climate

  • Book: Soil not Oil: Climate Change, Peak Oil and Food Insecurity by Vandana Shiva

  • Book: So Shall We Reap: What's Gone Wrong with the World's Food and How to Fix It by Colin Tudge

Activity 2

Record a few sentences about your response to these visions of a new ecological agriculture.

5 How do we adapt in our cities?

Until relatively recently, cities were intimately connected to the sources of food that sustained their populations.

As the architect Carolyn Steel explains in her podcast, Hungry City, Supplying the City, in pre-industrial cities the complicated nature of managing a food supply was the key determining factor in the decision about where cities could be located and how big they could grow. These days the intricate web of our food supply is largely invisible to us, managed by corporations rather than our civic authorities. The ‘just-in-time’ nature of the global supply chains leaves even the most affluent countries vulnerable to insecurity of supply.

Sitopia and the role of collaboration

If we start to consider how we might use food itself as a tool for creating sustainable cities we have a very powerful tool for shaping a positive future for the planet. This concept is what Carolyn Steel calls ‘Sitopia’. Listen to Carolyn Steel talk about sitopia.

A pioneering community in London is using food to influence change towards a more sustainable London. Growing Communities is a group of Hackney residents who run an organic vegetable box scheme, farmers market and urban vegetable-growing sites. They are taking back control of their food system in their community by setting up trading mechanisms that both employ local people and support organic and fair-trade farmers further afield. Their systems for trade in food are articulated through their concept of ‘Food Zones’, illustrated in a diagram in this document.

The concept of sitopia is grounded in the idea of food subsidiarity: raising what we can as close to the centres of habitation as we can, taking into account a number of factors such as:

  • soil type

  • climate

  • what grows best where

  • size of plots available

  • infrastructure and transport links available

  • the degree of mechanisation that makes most sense

  • the perishability of the produce.

However, this isn’t simply a call to grow more food in cities, though it very much starts with that.

Growing Communities’ food zones manifesto asserts that as individuals we can direct our purchasing power through joining together with others in our community to support existing farmers and growers, giving them a market for their food at a fair price and in turn being able to influence the way in which food is grown. In this way we could radically alter the future of farming, making it less fossil fuel dependent, healthier and more sustainable. In this way too, instead of cities being part of the problem, they could become part of the solution.

See the Growing Communities Food Zones Manifesto at their website.

Agriculture has always been practised in and around cities but in the West we have become used to farming being confined to the countryside. Relatively recently there has been a renaissance in urban agriculture, which encompasses a wide range of physical spaces and productive food stuffs from back gardens to aquaculture and vertical farming.

This family of four in Pasadena, California are managing to grow almost all of their summer-time diet from their fifth of an acre back garden. See their video, Path to Freedom – Urban Homestead, on YouTube.

This form of urban agriculture in back gardens is being explored not only as a step towards self-sufficiency, but also as a service that could provide viable and sustainable urban livelihoods.

Another example you can view on YouTube is My Farm, a video created by Community Supported Agriculture, San Francisco.

The relatively low-tech, community-based examples above contrast with this short film, Urban Aquaculture, about high-tech methods of raising fish for food in urban buildings.

Activity 3

The following video shows a debate between architects on how cities will feed themselves in the future. It features a proponent of ‘vertical farming’ – a system of stacking greenhouses or animal feedlots on top of each other and recycling nutrients by growing hydroponically or making biogas energy from animal manures. This contrasts sharply with the visions of a low carbon farming future discussed in this unit.

Watch the National Building Museum of America's debate on how cities will feed themselves in the future.

Consider the social and cultural aspects of agriculture and how they might be reconciled with urban agriculture. Also consider the implications of urban agriculture for animal welfare. Bearing these considerations in mind, make a list of the pros and cons of producing food in an urban environment.

Identify the questions that this unit has left you with that you would like to explore further.

  • Are you motivated to make changes to your lifestyle now that you have learnt about how agriculture will need to change in order to mitigate climate change?

  • What motivates you to take action?

  • Is there anything holding you back?


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Unit authored by Alissa Pemberton

Unit image

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All links accessed 30 November 2009.