Organically farmed food has a bigger climate impact than conventionally farmed food, due to the greater areas of land required, a new study finds.
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. Although direct emissions from organic agriculture are often lower, due to less use of fossil energy, among other things, the overall climate footprint is definitely greater than for conventional farmed foods.
The 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.
The reason why organic food is so much worse for the climate is that the yields per hectare are much lower, primarily because fertilizers are not used. To produce the same amount of organic food, you therefore 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.
Even organic meat and dairy products are, from a climate point of view, worse than their conventionally produced equivalents.
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 takes into account 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.
For consumers who want to contribute to the positive aspects of organic food production, without increasing their climate impact, an effective way is to focus instead on the different impacts of different types of meat and vegetables in our diet. Replacing beef and lamb, as well as hard cheeses, with vegetable proteins such as beans, has the biggest effect. Pork, chicken, fish and eggs also have a substantially lower climate impact than beef and lamb.
In organic farming, no fertilizers are used. The goal is to use resources like energy, land and water in a long-term, sustainable way. Crops are primarily nurtured through nutrients present in the soil. The main aims are greater biological diversity and a balance between animal and plant sustainability. Only naturally derived pesticides are used.
The arguments for organic food focus on consumers' health, animal welfare, and different aspects of environmental policy. There is good justification for these arguments, but at the same time, there is a lack of scientific evidence to show that organic food is in general healthier and more environmentally friendly than conventionally farmed food.
Today's major investments in bio-fuels are also harmful to the climate because they require large areas of land suitable for crop cultivation, and thus, according to the same logic, increase deforestation globally, the researchers in the same study argue.
For all common biofuels (ethanol from wheat, sugar cane and corn, as well as biodiesel from palm oil, rapeseed and soya), the carbon dioxide cost is greater than the emissions from fossil fuel and diesel, the study shows. Biofuels from waste and by-products do not have this effect, but their potential is small, the researchers say.
All bio-fuels made from arable crops have such high emissions that they cannot be called climate-smart, according to the researchers