For social and environmental reasons, many consider buying organic products. This indeed fosters more sustainable agricultural practices. However, when computing one's carbon footprint, it is not uncommon to observe an increase in greenhouse gas emissions or, in the best cases, no significant reduction in emissions after replacing conventional products with organic ones.
Why doesn't the switch to organic products necessarily lead to a reduced carbon footprint?
What Factors Influence Greenhouse Gas Emissions?
For various reasons, the impact of organic farming on greenhouse gas emissions is more nuanced than one might think. Depending on the type of product, the farming method, and the scale of production, differences in emissions between conventional and organic agriculture can vary significantly.
Type of Agriculture and Geography - The example of coffee production in Central America. A study comparing the impact of conventional and organic coffee production [1] shows that differences in farming intensity have a significant impact on greenhouse gas emissions. In Nicaragua, intensive organic coffee farming can result in higher emissions than moderate conventional farming of the same product. Conversely, in Costa Rica, both intensive and moderate organic coffee production result in lower emissions compared to conventional farming. In general, for a given farming method, intensive agriculture tends to result in higher emissions than moderate agriculture.
Type of Product - The example of rice. Researchers have studied emissions differences between organic and conventional rice production throughout its lifecycle [2]. Organic rice systematically results in more GHG emissions than conventional rice. While CO2 emissions are lower in conventional farming than in organic farming, emissions of other greenhouse gases (N₂O and CH4) were significantly higher, mainly due to differences in fertilizer use.
Therefore, GHG emissions resulting from organic farming can either increase or decrease depending on the product.
Scale: A study in the United Kingdom [3] demonstrated that organic farming reduced greenhouse gas emissions within their specific farming model. However, if organic farming were scaled up to a national level, food production would decrease by 40%, leading to increased food imports from abroad to compensate for the loss in production. Land-use changes related to this transition could generate new GHG emissions, thereby increasing the overall emissions from organic farming at the national level. Thus, while organic farming may have benefits at a moderate scale, implementing it at a national scale might limit these advantages.
However, it is important to note that the reduction in the agricultural yield only occurs when preserving traditional modes of agriculture and consumption. A study published in Nature in 2017 [4] shows that a transition to 100% organic farming by 2050 would be possible, provided that we change our production and consumption habits. For instance, shifting from monoculture to polyculture would reduce the use of nitrogen fertilizers while maintaining yields, and reducing meat consumption would free up agricultural land for human consumption. Therefore, scaling up organic farming is not necessarily destined to increase greenhouse gas emissions.
So, does organic farming significantly emit fewer greenhouse gases than conventional farming?
As we've seen, greenhouse gas emissions from organic farming depend on numerous factors. Reduced yields compared to conventional farming are the primary reason for the increase in emissions in organic farming, as it leads to the use of more natural fertilizers and changes in land use. Product origin also has an impact, although it is relatively minor compared to other stages of production.
A study comparing life cycle impacts of several organic products [5] illustrates the complexity of the issue. As shown in the graph below, no consensus exists to definitely conclude regarding the environmental performance of organic farming.
Therefore, the impact of greenhouse gas emissions from organic farming compared to conventional farming varies widely, depending on several factors. While organic farming has undeniable environmental benefits, it is important to recognize that it does not automatically result in significantly lower greenhouse gas emissions. Both farming approaches have distinct environmental consequences and should be evaluated on a case-by-case basis to determine their true impact on emissions.
Organic or not ?
Although the impact of organic farming on greenhouse gas emissions may not be significant, organic farming offers numerous advantages in other areas.
The chart below [6] illustrates the performance of organic farming (represented by the petals) compared to conventional farming (represented by the red circle).
Variables that could not be quantified are in grey.
In intensive conventional agriculture, pesticides are commonly used to protect crops. Unfortunately, these chemicals have adverse consequences, including soil, water, and air contamination, the destruction of pollinators, and notable health impacts on humans.
Organic farming stands out in the following ways:
Better for health: Pesticide residues can be found in food, and in agricultural land, these pesticides are also present in the air. Numerous studies suggest a link between pesticide exposure and developmental cognitive delays, increased susceptibility to leukaemia in children, and an elevated incidence of certain cancers (e.g., lung, prostate) among farmers.
Biodiversity Protection: In the European Union, 24.5% of vulnerable or endangered species are threatened by agricultural effluents (including pesticides and fertilizers). In France, over 70% of grey partridge nests are exposed to at least one pesticide.
The decline in the population of a particular species can trigger disruptions that jeopardize the entire balance of an ecosystem.
Organic farming prohibits the use of synthetic chemical pesticides. In Europe, for example, approximately 98% of organic farming areas are free of these pesticides, which promotes a more diverse fauna and flora. Organic farming often encourages the creation of buffer zones, hedges, and natural meadows, serving as sanctuaries for wildlife and contributing to biodiversity preservation.
Soil and Groundwater Protection: Organic farming prioritizes the management of organic matter, using natural amendments such as compost and manure. This enhances soil structure and water retention. Organic soils can store up to 28% more carbon than conventional soils. Reduced or no-till practices in organic farming help prevent soil erosion. In comparison, conventional agriculture can result in soil erosion rates 10 to 100 times higher.
The absence of synthetic chemical pesticides and fertilizers in organic farming limits the risk of groundwater contamination. Studies have shown that pesticides are present in 44% of groundwater in Europe, but are much less frequent in organic farming areas.
What to choose?
While the impact on the carbon footprint may not always be significant, Greenly encourages its customers to move towards more environmentally-friendly production methods. For its many advantages, transitioning to organic farming is highly recommended.
Regarding greenhouse gas emissions, try avoiding highly emissions-intensive food products (see list below), favour legumes, seeds, soy, vegetarian diets over meat-based diets and dairy products such as cheese, for example.
One should also strive to adopt sustainable sourcing practices: favour local and seasonal fruits and vegetables, check the origin of products, support local producers, promote permaculture, and choose organic products.
The transition is in your hands!
Resources
[1] Greenhouse gas emissions in coffee grown with differing input levels under conventional and organic management
Martin R.A. Noponenab,1, Gareth Edwards-Jonesae, Jeremy P. Haggarbc, Gabriela Sotob, Nicola Attarzadehad, John R. Healey
[2] Environmental Life Cycle Assessment in Organic and Conventional Rice Farming Systems: Using a Cradle to Farm Gate Approach
Elnaz Amirahmadi, Jan Moudrý, Petr Konvalina, Stefan Josef Hörtenhuber, Mohammad Ghorbani, Reinhard W. Neugschwandtner, Zhixiang Jiang, Theresa Krexner and Marek Kopecký
[3] The greenhouse gas impacts of converting food production in England and Wales to organic methods Laurence
G. Smith, Guy J.D. Kirk, Philip J. Jones & Adrian G. Williams
[4] Strategies for feeding the world more sustainably with organic agriculture
Adrian Muller, Christian Schader, Nadia El-Hage Scialabba, Judith Brüggemann, Anne Isensee, Karl-Heinz Erb, Pete Smith, Peter Klocke, Florian Leiber, Matthias Stolze & Urs Niggli
[5] Comparison of organic and conventional cropping systems: A systematic
review of life cycle assessment studies
Martina Boschiero, Valeria De Laurentiis, Carla Caldeira, Serenella Sala
[6] Many shades of gray—The context-dependent performance of organic agriculture
Verena Seufert and Navin Ramankutty