Carbon farming is the process of adopting sustainable agricultural methods and land use techniques to increase the absorption of carbon in the soil, crops and crop roots, trees and leaves, to reduce greenhouse gas emissions from livestock, soil, and vegetation (avoidance).
Carbon farming focuses on techniques such as the use of zero-till agriculture or planting crop types that increase the ability of the soil to store, or sequester, more carbon dioxide (and other greenhouse gases), or ensure they stay trapped underground.
Agriculture, forestry and land use directly account for 18.4% of total greenhouse gas (GHG) emissions, according to Our World in Data. In the United States, the agriculture sector directly contributes to 9% of total national emissions, while for Canada, the figure is 10%.
Yearly emissions from crops and livestock and related land use, and share of agriculture in global GHG emissions from all sectors, 2000–2018. Source: FAOSTAT 2020.
Conversely, agriculture helps slow climate change by storing carbon on agricultural lands. The carbon that plants absorb from the atmosphere via photosynthesis gets absorbed into the soil and can remain there for centuries if not disturbed. However, while this may be possible in protected forests, not disturbing the soil at all is not an option on farmlands. However, but soil disturbance can certainly be reduced by adopting better tactics to manage the soil. For instance, minimal tillage, adopting practices such as cover crops or crop rotation, or leaving crop residues on the field help soils store more carbon.
“Carbon farming is the way forward to soak up excess CO2 and help reverse climate change for the betterment of the next generation,” says Jon Bradbury, Chief Financial Officer, CarbonTerra.
A 2017 study had found that nature-based climate solutions could provide up to one-third of the emissions reductions required under the Paris Accord. These include increasing carbon sequestration and reducing emissions of carbon and other greenhouse gases through conservation, restoration, and improved management practices in forest, wetland, and grassland biomes.
“Greenhouse gases have been raising at an alarming rate that many of the countries have tried to implement protocols for reducing GHG emissions. Farmers, who already feed the world are in a unique position to offset this emission by farming best practices,” underlines Dr. Sivasathivel Kandasamy, Lead Data Scientist, CarbonTerra.
How Does Farming Lead to GHG Emissions?
The main gases emitted by agricultural activities are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O).
Sources of greenhouse gas emissions from agriculture (excluding CO2 emissions associated with energy use). Source: Agriculture and Agri-Food Canada.
These greenhouse gases differ in their ability to trap heat. While carbon dioxide is the most infamous of the greenhouse gases, because of its prevalence in the atmosphere, methane is more than 20 times worse when it comes to trapping heat, nitrous oxide is about 300 times worse. For the purpose of standardization, emissions for methane and nitrous oxide are usually taken in terms of their carbon dioxide equivalents. For instance, methane is 20 CO2 equivalent (20CO2e) while nitrous oxide is 298 CO2 equivalent (298CO2e).
Since carbon is stored in the soil, any disturbance of the land or the roots of the vegetation, like tilling, leads to emissions. Further, many regular farming methods and activities also lead to emissions. For instance, carbon dioxide is mainly released through regular activities like the burning of crops or organic matter, decay of plant and organic matter and insect and microbial activity in soils.
According to the Food and Agriculture Organisation (FAO), global emissions due to agriculture (including related land use/land use change), were 9.3 billion tonnes of CO2 equivalent in 2018. Further, methane and nitrous oxide emissions from crop and livestock activities contributed 5.3 billion tonnes of CO2 equivalent in 2018, an alarming growth of 14% since 2000.
Contribution of crops and livestock activities to total non-CO2 emissions from Agriculture. Source: FAOSTAT 2020.
Nitrous oxide is emitted directly from fertilizers and manure, decomposition of crop residue or cultivation of organic soils, while there can also be indirect nitrous oxide emissions from the re-deposition of ammonia and from nitrogen leaching. Nitrogen leaching happens when the water content in the soil becomes greater than its water holding capacity and the excess water drains below the root zone carrying within it soluble nitrogen, mostly as nitrate.
Methane emissions in farming are usually from animal farming and the decomposition of stored manure. When organic matter in feed or manure decomposes, a portion is released as methane.
How Can Carbon Farming Help Reduce Emissions?
Even though agriculture is a key contributor to carbon emissions, it is also one sector which has the potential to transform itself from a net carbon emitter to a net carbon absorber.
According to Jim Skea, Co-Chair of IPCC Working Group III, “Agriculture, forestry and other types of land use account for 23% of human greenhouse gas emissions. At the same time, natural land processes absorb carbon dioxide equivalent to almost a third of carbon dioxide emissions from fossil fuels and industry.”
This is where carbon farming comes in. Carbon farming techniques can help remove carbon dioxide from the atmosphere and store it for long periods of time in soil, microorganisms, and plant matter. IPCC found soil carbon sequestration has the ability to reduce CO2 at the lowest cost – USD 0 to USD 100 per ton – while estimating that this could remove between 2 and 5 gigatonnes of CO2 equivalent per year by 2050.
Since agricultural soils can both emit or absorb carbon dioxide, the carbon credit of farmland is determined by calculating the difference between the emissions to the atmosphere due to natural causes and various farming practices, and the net CO2 absorption by the same farmland, whether naturally or via the adoption of sustainable farming techniques.
Carbon farming could be said to be successful when carbon storage resulting from such sustainable farming methods and land management exceeds the amount of emission from the piece of land.
The Natural Resources Conservation Service under the United States Department of Agriculture has developed 35 conservation practices that improve soil health and sequester carbon while producing other important environmental co-benefits, including hydrological function, biodiversity, ecosystem resilience and productivity.
How Can Farmers Benefit From Carbon Farming?
Adopting carbon farming typically involves a cost. It may be easy for commercial farm groups to quickly adopt such farming practices. However, as we noted in our previous blog, for an average farmer, adopting these practices is challenging in terms of costs and adoption. Such individual land owners and farmers need incentives to switch to integrated carbon sequestering techniques by giving up their age-old practices.
While this can happen via government policies, the agriculture sector is now viewing the carbon credit market as a great opportunity.
A carbon credit is a transferrable instrument certified by authorities representing an emission reduction of one metric tonne of carbon dioxide (CO2), or an equivalent amount of other GHGs, from the atmosphere.
So, when a farmer adopts carbon farming techniques and earns carbon credits on his farmland, he can sell these at a cost to a large corporation, say a power plant, which is looking to offset its emissions by buying carbon credits. For instance, Microsoft last year announced it would buy carbon offsets worth up to $2 million as part of its effort to become carbon negative by 2030.
The biggest buyers of carbon offsets are often the largest emitters, such as power, oil or transportation companies. In fact, the carbon offset market is so lucrative that oil and gas giant Shell 2020 acquired a carbon farming company in Australia, Select Carbon, to meet its 2050 net-zero ambitions.
“Carbon currency and crediting provide valuable instruments to sustain an economy that values carbon storage and sequestration in soils and biomass. Regenerative and smart agriculture offer avenues to create carbon-neutral industries with farmland serving as carbon sinks,” Dr. Sabine Grunwald, Professor, Pedometrics, Landscape Analysis & GIS Laboratory, and Soil and Water Sciences Department, IFAS, University of Florida.
The global voluntary carbon offsets market size was estimated to reach a record of USD 6.7 billion at the end of 2021, according to September 2021 report from Ecosystem Marketplace. The report also noted that the year 2021 logged a new market value record of over USD 1 billion in voluntary carbon credit transactions.
Farmers are relatively new entrants to this booming carbon offset market.
Canada is already a global leader in “quantifying agricultural emissions reduction” with its carbon offset markets providing the “largest number of opportunities in the world for farmers to participate”, according to a statement from the Trade Commissioner in January 2022.
In July last year, the Canadian government announced an investment of up to CAD 621,572 to develop an assurance system for farmers to produce and sell carbon offsets. The Canadian Forage and Grassland Association expect that more than 5,000 hectares of Canadian grasslands will be protected by land conservation agreements, and 10,000 tonnes of carbon dioxide equivalent will be saved through third-party verified carbon offset credits.
As various countries come up with various policies, the market will quickly evolve as corporate giants attempt to reduce their own carbon footprint by paying farmers to offset their own carbon emissions. It’s a win-win for all.