Climate and Energy

Due to the capacity of plants to absorb the greenhouse gas CO2 and soils to sequester carbon, agriculture could in the long term theoretically feed us in a climate neutral way and, in the short term, even sequester more CO2 than it emits. Instead, the agricultural sector is one of the world’s most significant sources of anthropogenic greenhouse gas emissions. The activities predominantly responsible for the devastating carbon footprint of food production are the clearing of forests and the conversion of grassland into arable land. Other drivers are the emission of extremely potent greenhouse gases such as nitrous oxide from the decomposition of mineral fertiliser, as well as methane from rice production and the digestive process of ruminants in livestock farming."Agriculture contributes to climate change in several major ways including:
• Land conversion and plowing releases large amounts of stored carbon as CO2 from vegetation and soils. About 50% of the world's surface land area has been converted to land for grazing and crop cultivation resulting in a loss of more than half of the world's forests.
• Deforestation and forest degradation releases carbon through the decomposition of aboveground biomass and peat fires and decay of drained peat soils.
• Carbon dioxide (CO2) and particulate matter are emitted from fossil fuels used to power farm machinery, irrigation pumps, and for drying grain, etc., as well as fertilizer and pesticide production.
• Nitrogen fertilizer applications and manure applications as well as decomposition of agricultural wastes results in emissions of nitrous oxide (N2O).
• Methane (CH4) is released through livestock digestive processes and rice production.
• Altered radiative fluxes and evaporation from newly bare soils.
• Increased geographical distance between producer and consumer, together with regional agricultural specialization, has resulted in greater energy use for transportation." (Synthesis, p. 46-47).
The Intergovernmental Panel on Climate Change (IPCC) attributes 31% of global greenhouse gas emissions directly to agriculture and land use changes. If the processing of food, its transport, storage, cooling and disposal are added, which the IPCC ascribes to other sectors, more than 40% of all emissions depend on the way we farm and eat. Agriculture therefore plays a crucial role if the target of limiting global warming to 2 degrees, through a drastic reduction of global greenhouse gas emissions, is to be achieved. The climate footprints of different cultivation methods and food systems vary enormously."The highest emissions of greenhouse gases from agriculture are generally associ­ated with the most intensive farming systems." (Synthesis, p. 47)

Savings potentials and storage capacity

In general, labour-intensive small-scale farming is more climate-friendly than industrial monocultures. Small-scale systems producing for local markets and direct consumption have a lower climate impact than large-scale commodity production with complex transport, processing and cold chains. The IAASTD sees the greatest potential in a more climate-friendly form of soil management: Arable land must not lie fallow and a permanent vegetative soil cover should be maintained. Tillage and the depth of ploughing have to be reduced to a minimum. The systematic build up of organic matter will increase the carbon-storage and water holding capacity, as well as the fertility of the soil at the same time. For this purpose, crop residues should be tilled into the ground instead of leaving them for decomposition at the surface or burning them. The integration of trees into farming through agroforestry systems could also make an important contribution."Some "win-win" mitigation opportunities have already been identified. These include land use approaches such as lower rates of agricultural expansion into natural habitats; afforestation, reforestation, increased efforts to avoid defor­estation, agroforestry, agroecological systems, and restora­tion of underutilized or degraded lands and rangelands and land use options such as carbon sequestration in agricultural soils, reduction and more efficient use of nitrogenous inputs; effective manure management and use of feed that increases livestock digestive efficiency." (Synthesis, p. 9)In the end, the capacity of different soils to sequester carbon is of course limited. The actual prevention of greenhouse gas emissions cannot be replaced. The most important measures to achieve this are reducing the use of mineral fertiliser and substituting chemical fertiliser with green manure and organic matter, as well as using natural pest control instead of chemical herbicides and insecticides. Further saving potential lies in the optimisation of cultivation methods, irrigation systems and the keeping and feeding of livestock. Deforestation must be stopped and under-utilised or degraded land should be reafforested. The drainage of moors and peat soils, which sequester large amounts of carbon, must be avoided or reversed. >>more

Facts & Figures

In 2012, global greenhouse gas emissions amounted to 54 gigatonnes of carbon dioxide equivalent (GtCO2e). Under a business-as-usual scenario, emissions are estimated to rise to 59 GtCO2e in 2020 and 87 GtCO2e in 2050. In order to have a likely chance of staying within the 2 °C target, emissions must not be higher than 44 GtCO2e by 2020. The agricultural sector could help closing the gap with an emission reduction potential of up to 4.3 GtCO2e t in 2020.

In 2013, the amount of greenhouse gases in the atmosphere reached the highest level since pre-industrial times. Between 2012 and 2013, carbon dioxide emissions increased by 2.9 parts per million (ppm) to 396 ppm. The global average for methane increased to 1824 parts per billion (ppb) in 2013 and the burden of nitrous oxide reached 325.9 ppb - 20% higher than in the pre-industrial era, mainly as a result of the use of nitrogen-containing fertilisers, including manure.

Each year, 30% of global food production - almost 1.3 billion tonnes - is lost after harvest or wasted in retail and households. The direct economic cost of food wastage is $750 billion in terms of producer prices. Environmental costs add another $700 billion. The carbon footprint of wasted food is 3.3 GtCO2e (without emissions from land use change). The global blue water footprint of food wastage is about 250 km³. Produced but uneaten food vainly occupies almost 1.4 billion hectares of land.

In the EU, food waste along the supply chain is estimated at 89 million tonnes or 180 kg per person per year. Households produce the largest share of EU food waste (42%), followed by agriculture/food processing (39%), food service/catering (14%), and retail/wholesale (5%). This calculation excludes agricultural food waste, which may amount to a similar volume.

The livestock sector plays an important role in climate change. Livestock are responsible for 6 to 32% of greenhouse gases (Meat Atlas, p. 34), depending on whether the measurement is based only on direct emissions or includes emissions from the production of feed, fertiliser and pesticides, as well as forest clearance to grow soybeans. According to the FAO, the livestock sector emits 7.1 GtCO2-eq per year, representing 14.5% of all human-induced emissions.

Food systems contribute 19%–29% of global anthropogenic greenhouse gas (GHG) emissions, releasing 9,800–16,900 megatonnes of carbon dioxide equivalent (MtCO2e) in 2008. Agricultural production, including indirect emissions associated with land-cover change, contributes 80%–86% of total food system emissions, with significant regional variation.

In the European Union, the agricultural sector produced 461 million tonnes of CO2 equivalents in 2011, e.g. through enteric fermentation and manure management. This accounts for 10% of the total EU-27 emissions for that year (emissions from land use change, agricultural transport and energy use are excluded). Germany and France together produced 35% of all agricultural emissions.

Organic agriculture provides environmental benefits through the sequestration of atmospheric carbon in soil organic matter. Soil organic carbon stocks were 3.5 metric tonnes per hectare higher in organic than in non-organic farming systems. Organic farming systems sequestered up to 450 kg more atmospheric carbon per hectare and year through CO2 bound into soil organic matter.

Institutions

  • IPCC Intergovernmental Panel on Climate Change published the Fifth Assessment Report in 2014
  • UNEP United Nations Environment Programme works on climate change
  • UNFCCC United Nations Framework Convention on Climate Change
  • FAO - Climate Change offers news and publications on climate change
  • Climate-smart agriculture is a concept promoted by the FAO
  • CCAFS CGIAR Research Program on Climate Change, Agriculture and Food Security, collects facts on food emissions
  • Save Food global initiative on food loss and waste reduction
  • IFPRI research institute working on climate change and food security
  • EEA European Environment Agency on climate change
  • IEA International Energy Agency publishes annual key world energy statistics

Civil Society

Literature

Videos: Climate and Energy

Click on the image to watch the videos
Click on the image to watch the videos

Facts about livestock production and global warming

Graphics

  • UNEP Greenhouse gas emissionsUNEP Greenhouse gas emissions
  • Human influenesHuman influenes
  • UNEP Emissions from agricultureUNEP Emissions from agriculture
  • UNEP Regional CO<sub>2</sub> emissionsUNEP Regional CO2 emissions
  • UNEP Coastal vulnerabilityUNEP Coastal vulnerability
Share |

Donors

Donors of globalagriculture
English versionDeutsche VersionDeutsche Version