A new international study into the impact of agricultural land use on climate change has found organic food production is worse for the climate than conventional farming, due to the fact that it needs greater areas of land to grow produce.

The new research developed a novel metric for calculating the carbon footprint of specific land use. Called a "carbon benefits index," this calculation measures the agricultural output of a given hectare of land in terms of volume of product and carbon dioxide emissions. Homing in on the differences between organic food production and conventional food production, the study concludes that due to organic farming's inefficient yields, it generally results in a greater environmental impact than conventional farming methods.

"The greater land-use in organic farming leads indirectly to higher carbon dioxide emissions, thanks to deforestation," explains Stefan Wirsenius, a Swedish researcher working on the study. "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," says Wirsenius.

The climate impact from Swedish wheat and peas produced organically, compared with conventional farming methods Stefan Wirsenius/Chalmers University of Technology

This isn't the first study to raise questions over the greater environmental cost of organic farming recently. As the world's population rapidly grows many scientists are trying to balance the increasing demand for food with better agricultural production methods. A large study published earlier this year called for more efficient "high-yield" farming to better make use of land already cleared for the purpose.

"Our results suggest that high-yield farming could be harnessed to meet the growing demand for food without destroying more of the natural world," says Andrew Balmford, lead author on this earlier study. "However, if we are to avert mass extinction it is vital that land-efficient agriculture is linked to more wilderness being spared the plough."

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 Yen Strandqvist/Chalmers University of Technology

Of course trying to calculate the environmental impact of a person's individual diet is a little more complicated than simply suggesting they don't eat organic food. The biggest impact one can individually make is perhaps leaning towards a more plant-based diet.

"The type of food is often much more important. For example, eating organic beans or organic chicken is much better for the climate than to eat conventionally produced beef," says Wirsenius.

And organic meat production presents even more complicated considerations. It may be reasonable to assume organic grass-fed beef is better from an animal welfare perspective, but a 2017 study calculated grass-fed beef requires more land than grain-fed beef, while offering no decreases in comparable greenhouse gas emissions. All this means is that from a carbon emission perspective, conventional animal farming may be better for the environment than organic.

So where does this leave a person who is trying to live the most ethical, environmentally sensitive life possible? It is hard to say, but it is becoming increasingly clear that due to inefficient yields the world's food production could not sustain organic farming on a mass scale without clearing more land.

"Organic food does have several advantages compared with food produced by conventional methods," Wirsenius notes. "For example, it is better for farm animal welfare. But when it comes to the climate impact, our study shows that organic food is a much worse alternative, in general."

The new study was published in the journal Nature.

Source: Chalmers University of Technology

Update (Dec. 18, 2018): After receiving numerous comments questioning the funding of the research, we reached out to Stefan Wirsenius, one of the researchers responsible for the study, for clarification. He reiterated that the research "had no financial support or links to industries and economic interests linked to conventional farming."