What climate change mitigation means & why it matters to agriculture
When agricultural producers adjust their farm practices and/or equipment to reduce their greenhouse gas emissions or to sequester (store) carbon in soils or vegetation, they are engaging in greenhouse gas mitigation. Greenhouse gas mitigation is any activity that reduces or removes emissions from the environment.
In a global context, agriculture is thought to have significant potential for mitigating climate change with respect to reduction, sequestration and avoidance of emissions, described below. In order to quantify changes in emissions, tools exits to measure emissions both before and after on-farm mitigation activities. Provincial and national emissions inventories allow tracking and reporting out of emissions on a broader scale, across the entire agriculture sector.
Reduction of emissions
Greenhouse gas emissions from agricultural activities can be reduced through more efficient management of the carbon and nitrogen flows within agricultural systems. The farm management practices best suited to emission reduction are region and site specific. However, some practices are commonly recognized for minimizing greenhouse gas emissions and many of these are identified within this section of this website.
Enhancement of removals (sequestration)
Ecosystems associated with agriculture are known to hold substantial carbon reserves; primarily in soil organic matter. Certain farm practices can facilitate increased plant uptake or soil storage of carbon (or reduce the loss of stored carbon). These practices are known as carbon sequestration or the creation of carbon “sinks”. In particular, agroforestry systems and perennial plantings may store significant quantities of vegetative carbon. Only vegetation that is retained over the long term is effective in storing carbon.
Avoidance (displacement of emissions)
The agricultural sector can potentially assist society to avoid (or displace) greenhouse gas emissions. Fuels produced from crops and agricultural residues/by-products can displace fossil fuels and enable emission reduction at the combustion stage.
Measuring GHG emissions
Measuring greenhouse gas emissions in agricultural production systems is often complex. This is due, in part, to the broad range of agricultural practices and the variables of soil, climate and land cover. Some agricultural emissions are in flux and may be difficult to measure, for example, the management of carbon and nitrogen flows within agricultural systems. The more straightforward elements of agricultural and food processing emissions are consumption of energy and transportation fuels.
Greenhouse Gas Emission Calculators
Researchers at Agriculture and Agri-Food Canada have developed the Holos Greenhouse Gas Emission Calculator which is a software program that estimates emissions based on information entered for an individual farm. Holos is intended to enable Canadian farmers to assess their greenhouse gas emissions and to determine how various adjustments might alter emissions. The calculator estimates carbon dioxide, nitrous oxide and methane emissions associated with a range of farm systems, as well as carbon storage and loss for various land use and management practices. The current version of the Holos Greenhouse Gas Emissions Calculator (version 1.1.2) is available online and can be downloaded free of charge.
As part of the Kyoto protocol, many countries have developed inventories to identify and report sources of greenhouse gas emissions. Despite its withdrawal from the Kyoto protocol, Canada maintains a national inventory of greenhouse gas emissions for the purpose of reporting to the United Nations as a commitment under the non-binding United Nations Framework Convention on Climate Change. In British Columbia, consistent with the provincial regulation that also identifies emission reduction targets (Greenhouse Gas Emissions Target Act) an inventory has been developed and is continually being refined. This inventory also feeds into the broader national level reporting. Overall, BC agriculture is a relatively small contributor to greenhouse gas emissions. In 2012 only 3.3% of the greenhouse gas emissions within the BC inventory were attributed to agriculture. The majority of individual agricultural operations in BC have low (and diffuse) emissions, which means they are unlikely to be regulated through pending emission thresholds. Food processing, energy consumption on farms, and transportation associated with food products are currently incorporated into other parts of the inventory. However, these other sources are sometimes the focus of consumer groups concerned with emissions. For example, the emissions associated with “food miles” and energy consumption have received significant media/public attention.