The reason for the greater environmental impact, as Chalmers University of Technology researchers report, is due to the greater land use required for organic farming (assuming that produce from both types of farm have similar transportation distances and modes of carriage).
The study into different forms of farming has examined crops per hectare, and found this to be significantly lower in organic farming. In turn, this creates far more indirect carbon dioxide emissions due to deforestation. While direct carbon emissions from organic agriculture are typically lower than those from conventional farms, the overall climate footprint is much higher. The data drawn from the study came from Sweden, using statistics from the Swedish Board of Agriculture on the total production in Sweden, and the yields per hectare for organic versus conventional farming for the years 2013-2015.
Analyzing the data, the scientists came up with a new metric termed the “Carbon Opportunity Cost.” This metric was used to evaluate the effect of higher land-use and its contribution to higher carbon dioxide emissions arising from deforestation. This formula took into account the levels of carbon that is stored in forests (and the potential for this to be released as carbon dioxide following deforestation).
According to lead researcher, Stefan Wirsenius: “”Our study shows that organic peas, farmed in Sweden, have around a 50 percent bigger climate impact than conventionally farmed peas. For some foodstuffs, there is an even bigger difference — for example, with organic Swedish winter wheat the difference is closer to 70 percent.”
The researchers are keen to emphasize that their findings do not mean that conscientious consumers should switch to buying non-organic food, for there are other benefits relating to the production and consumption of organic food, especially in relation to animal welfare. There are also qualitative advantages with organic farming, which does not use synthetic or petroleum-based pesticides or fertilizers. In turn the absence of these chemicals significantly reduces water and soil contamination and this protects wildlife.
The research has been published in the journal Nature. The research paper is “Assessing the efficiency of changes in land use for mitigating climate change.”
