If you eat organic food in the belief that you're helping the planet, this study suggests you might be doing more harm than good.
International researchers from Chalmers University of Technology looked at the impact of organic and conventional food production on the climate.
The team found that organic crops produce much lower yields, mainly because chemical fertilizers aren't used to boost the crops. As a result, in order to produce the same amount of organic food as conventional crops, you'll need much more land.
So far, exactly what you'd expect. If conventional farming didn't produce much greater yields, we wouldn't have moved away from organic farming in the first place.
However, this study concluded that organic food has a bigger impact on the climate than conventional food, due to the extra carbon dioxide emissions produced through the deforestation required as a result of less-efficient organic production.
“The greater land-use in organic farming leads indirectly to higher carbon dioxide emissions, thanks to deforestation,” Stefan Wirsenius, one of the authors of the study, said in a press release. “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.”
In the study published in Nature, the team found that organic peas farmed in Sweden have about a 50 percent bigger impact on the climate than peas farmed using conventional methods. For other foodstuffs there was an even bigger difference, with Swedish winter wheat being close to 70 percent.
The researchers evaluated the effect of greater land use on carbon dioxide emissions, which they call "Carbon Opportunity Cost". They took into account how much carbon is stored in forests that will be released as a result of deforestation, which they say has not been considered before when assessing the impact of organic food on the environment.
“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."
The team say that the findings apply to organic meat production too, as, for example, organic dairy cows are fed organic grains. People looking to reduce their climate impact shouldn't simply abandon organic food, however.
“The type of food is often much more important," Wirsenius says. "Eating organic beans or organic chicken is much better for the climate than to eat conventionally produced beef."
However, he added that organic farming can be better for farm animal welfare. "But when it comes to the climate impact, our study shows that organic food is a much worse alternative."