A study which claims that switching to 100% organic farming would increase greenhouse gas emissions has been criticized for portraying organic in a ‘false and negative light’.
In a report published this month in Nature Communications, researchers from Cranfield University acknowledge that organic farming creates lower overall greenhouse gas (GHG) emissions – up to 20% lower for crops and 4% for livestock. But they say that lower yields achieved by organic crops means that food production levels are reduced.
In the 100% organic scenario, the Cranfield team says that resulting undersupply in the UK would result in up to five times more land being used overseas, and overall GHG emissions rising by 21%.
The researchers also question the importance of one of organic farming’s most frequently cited climate change mitigation benefits: an ability to ‘lock’ more carbon in the soil due to its greater use of manures and longer crop rotations.
The Cranfield team suggests these effects are ‘limited to the first decade or two following conversion to organic farming’, after which the soil moves to a steady-state when carbon sequestration rates fall to zero. Sequestration only offsets a small part of the higher emissions from overseas land use, the researchers claim.
But organic and sustainable farming groups have challenged the study findings – and the simplistic way they have been interpreted by the media. The Sustainable Food Trust says the study contains serious design flaws that cast farming in a ‘false and negative light in relation to global warming.
Another unfortunate case of researchers taking a myopic view of how agricultural production impacts climate change
IFOAM – Organics International said the study failed to acknowledge vital aspects of the relationship between food production and GHG emissions. For example, it doesn’t look at the potential of reducing food waste to fill any theoretical yield gap – despite food waste being itself responsible for as much as 10% of GHG emissions. Nor do the report’s authors look at the crucial question of dietary habits, instead noting: “Whether a different national diet could be provided by the same land area under all organic production is a different study.”
Louise Luttikholt, executive director of IFOAM – Organics International says: “We are in a climate crisis. We need responsible communication that puts issues into context, not one-sided debates that simply cannot lead to holistic solutions for sustainable food and farming”.
The US-based Organic Center says the study was ‘another unfortunate case of researchers taking a myopic view of how agricultural production impacts climate change’.
In a statement, the group says: “The study ignores food waste as a primary contributor to shortages in productivity, it glosses over the many mitigating effects organic has on climate change, and doesn’t take into account the positive trend of increased yields as research on organic techniques comes out. Taking a holistic view of our food system, conventional farming isn’t a viable option for long-term food security. It depletes our soil, destroys pollinator populations, and depletes carbon stores. Without ecological production systems like organic, we won’t be able to support food production in the long term.”