A new study has revealed that greenhouse gas emissions would go up if all farms in England and Wales went organic. Though the emissions of individual farms would go down, much more food would have to be imported as the amount they would produce would decrease substantially.
Image source: New Scientist
Yields would fall by nearly half if all food in England and Wales was produced organically. To meet this deficit, more farmland would be needed elsewhere in the world, which could double overall greenhouse gas emissions compared with those from farming in the two countries now.
“The key message from my perspective is that you can’t really have your cake and eat it,” says Laurence Smith, now at the Royal Agricultural University in the UK, who was part of the team that performed the analysis. Smith is a proponent of organic farming and says “there are a lot of benefits to the organic approach”. But his analysis shows organic farming has downsides too.
Farming and changes in land use – such as cutting down forests – are responsible for a third of all greenhouse gas emissions. That means reducing farming emissions and the land needed for farming is vital to limit further global warming.
According to the analysis by Smith and his colleagues, emissions per unit of food are on average 20 per cent lower for organic crops and 4 per cent lower for organic animal products.
The problem is that, on average, organic yields per hectare are lower, too. For wheat and barley, for instance, yields are just half of those of conventional farms. That means 1.5 times as much land would be needed to grow the same amount of food.
The estimated increase in emissions varies greatly depending on what assumptions are made about this extra farmland. If only half the extra land comes from turning grasslands into farms, the increase could be as low as 20 per cent. If grassland that would otherwise have been reforested is turned into farmland, emissions could nearly double.
“Organic farming has this greenhouse gas problem,” says team member Guy Kirk at Cranfield University in the UK. “You can’t ignore it.”
Source: New Scientist