A recent study looks at the carbon emission impact if England and Wales switched entirely over to organic farming. They found:

We predict major shortfalls in production of most agricultural products against a conventional baseline. Direct GHG emissions are reduced with organic farming, but when increased overseas land use to compensate for shortfalls in domestic supply are factored in, net emissions are greater. Enhanced soil carbon sequestration could offset only a small part of the higher overseas emissions.

In their model organic farming did not use fossil-fuel based fertilizer. The nitrogen comes from natural sources, like manure, and also rotation crops that fix nitrogen, such as legumes. This does result in a direct reduction in green-house gas (GHG) emissions, but also results in about a 40% decrease in crop production. That shortfall would have to be made up with increased imports, mostly from Europe. So then we have to calculate what it would take to replace the shortfall in production. This is where there is some variability in the model, because it depends exactly what land is converted to crop production. In the most likely scenarios there would be a net increase in GHG emissions of about 20%.

This is a great example of the law of unintended consequences. When dealing with any complex network, like agriculture, you have to consider the effects of any one change on the overall system. This is not the first study to show that organic farming is a net negative for the environment, and so it is in line with previous research. Further, the disadvantages of organic farming get worse as you try to scale it up.

For example, consider the nitrogen cycle – agriculture is largely a system of recycling nitrogen into food. So for any system you have to consider where all the nitrogen is coming from. Organic farming uses manure, but when the world’s agriculture was limited to manure as a source of nitrogen, that severely limited food production. The green revolution was largely created by the ability to make artificial fertilizer and therefore a non-manure based source of nitrogen. Bottom line – we cannot support the world’s population on manure.

Another source is rotating in crops that fix their own nitrogen from the atmosphere. The problem here is that this takes land away from crop production, so then you need more land overall for the same crop productivity. The problem here is that we are already using all the good arable land. Converting more land to farming is bad for the environment, further stresses ecosystems, and we are pushing into less and less productive land (because we’re already using all the good land for farming). So where is all this extra land to support organic farming going to come from? Even when limiting the evaluation to England and Wales we get into difficulty. But what if the world tried to go organic. We would need a second planet.

If anything, in order to protect ecosystems and mitigate climate change, we should be looking for ways to convert farmland back into grasslands and forests. This means making our farmland more productive, not less.

The numbers are pretty clear – so this is where organic proponents start to spin their logic:

“The assumptions behind the study’s conclusion that there will be a net increase in greenhouse gas emissions under organic are fundamentally flawed,” said Rob Percival of the Soil Association. “The study assumes no change in diet, which is clearly untenable given the global dietary health crisis, and that we would keep diverting most of our cropland to over-production of the wrong things – livestock feed, commodity crops for processed food and biofuels.”

The assumption of no change in diet is a feature, not a bug. That is exactly what a scientific study should do – isolate one variable and then see the impact of that variable. This is what organic proponents do all the time, try to distract from organic farming’s negative impact on land use and therefore the environment by obscuring it with a cloud of other unrelated changes. They are essentially arguing that you can offset the negative impact of organic farming through decreased meat production and other changes in the food system that would reduce demand. But that is not logical – you could do those things anyway. They are in no way tied to organic farming, and they do not change the fact that organic farming itself is a net negative. For example, one pro-organic study concluded we could feed the world with organic farming – but…

Mueller et al. use a food systems computer model to assess the environmental impacts of a theoretical conversion of world agriculture to 100 percent organic. This shows, based on estimates culled from the existing scientific literature, that global organic conversion would lead to a 16-33 percent increase in land use, with a corresponding 8-15 percent increase in worldwide deforestation. So how do the authors achieve their headline conclusion? By combining a worldwide conversion to organic agriculture with a heroic parallel worldwide conversion to vegetarianism, allowing them to assume (in some scenarios) a 100 percent reduction in land-area competition from animal production. This is combined with a similarly heroic 50 percent reduction in global food waste.

There is also a fundamental flaw in their plan which a systems analysis reveals – they want to simultaneously reduce meat production and increase reliance on manure as a nitrogen source. So – where is all that extra manure coming from? Do it with rotation cropping alone, and you need to significantly increase land use, which we don’t have unless you want to chop down the rain forest. If we could somehow magically reduce waste by 50% and dramatically reduce meat consumption, the benefits should be used to convert farmland to forest, not to organic farming.

It also needs to be pointed out that there is no reason to go organic. There is no health or other advantage. It is all just an appeal-to-nature fallacy in marketing.

I also find that extreme organic proponents do have another unrelated secret solution to the problem of low organic productivity – reduce world population. Another recent study found that a 100% organic system could only feed 5.9 billion people (world population is currently 7.5 billion and growing). This would mean a necessary reduction in population, which would happen naturally as two billion people starve to death.

The best way forward is to use farming practices that are the most productive and sustainable and have the least environmental impact. That is not organic farming, which does not prioritize these features but rather prioritizes “natural” methods, which are often arbitrary and often not the best practices. Organic farming is an unscientific harmful marketing gimmick that needs to be exposed for what it is.