It appears that what may be good for your diet may be messing up your environment. According to a study conducted by Chalmers University of Technology organic food could be worse for the climate than standard farming methods. “The crops per hectare are significantly lower in organic farming, which, according to the study, leads to much greater indirect carbon dioxide emissions from deforestation”, says Yen Strandqvist of Chalmers University of Technology.
The finding of an international study involving Chalmers University of Technology, Sweden, and published in the journal Nature, organically farmed food has a bigger climate impact than conventionally farmed food due to the greater areas of land required. Researchers developed a new method for assessing the climate impact from land-use, and used this, along with other methods, to compare organic and conventional food production. The results show that organic food can result in much greater emissions.
Stefan Wirsenius, an associate professor from Chalmers, states, “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.”
Reportedly, because fertilizers are not used, organic food is worse for the climate as yields per hectare are much lower. To produce the same amount of organic food, you need a much bigger area of land. The ground-breaking aspect of the new study is the conclusion that this difference in land usage results in organic food causing a much larger climate impact.
“The greater land-use in organic farming leads indirectly to higher carbon dioxide emissions, thanks to deforestation,” explains Stefan Wirsenius. “The world’s food production is governed by international trade, so how we farm in Sweden influences deforestation in the tropics. If we use more land for the same amount of food, we contribute indirectly to bigger deforestation elsewhere in the world.”
Even organic meat and dairy products are – from a climate point of view – worse than their conventionally produced equivalents, claims Stefan Wirsenius. “Because organic meat and milk production uses organic feeds, it also requires more land than conventional production. This means that the findings on organic wheat and peas in principle also apply to meat and milk products. We have not done any specific calculations on meat and milk, however, and have no concrete examples of this in the article.”
A new metric: Carbon Opportunity Cost
The researchers used a new metric, which they call “Carbon Opportunity Cost”, to evaluate the effect of greater land-use contributing to higher carbon dioxide emissions from deforestation. This metric considers the amount of carbon that is stored in forests, and thus released as carbon dioxide as an effect of deforestation. The study is among the first in the world to make use of this metric.
“The fact that more land use leads to greater climate impact has not often been taken into account in earlier comparisons between organic and conventional food,” says Stefan Wirsenius. “This is a big oversight, because, as our study shows, this effect can be many times bigger than the greenhouse gas effects, which are normally included. It is also serious because today in Sweden, we have political goals to increase production of organic food. If those goals are implemented, the climate influence from Swedish food production will probably increase a lot.”
So why have earlier studies not considered land-use and its relationship to carbon dioxide emissions? “There are surely many reasons. An important explanation, I think, is simply an earlier lack of good, easily applicable methods for measuring the effect. Our new method of measurement allows us to make broad environmental comparisons, with relative ease,” says Stefan Wirsenius.
From a sensors perspective, many platforms are available for assessing and analyzing these findings. Agritech makes extensive use of sensors to monitor and advance growing processes. Perhaps we will soon figure out how to deploy sensors that stimulate plant growth for greater organic yields. Of course, we should take into consideration a modicum of balance, meaning keeping production within realistic, useable levels as opposed to over production just for the sake of doing so. After all, we are looking at nature, in particular, the balance of nature.
The results of the study are published in the article “Assessing the efficiency of changes in land use for mitigating climate change” in the journal Nature. The article is written by Timothy Searchinger, Princeton University, Stefan Wirsenius, Chalmers University of Technology, Tim Beringer, Humboldt Universität zu Berlin, and Patrice Dumas, Cired.
For more information, contact Stefan Wirsenius, Associate Professor at the Department of Space, Earth and Environment, Chalmers University of Technology, +46 31 772 31 46, [email protected].