Conventional vs Organic Farming: Climate Protection

How does farming affect our environment and our daily lives? Read the introductory post to this series here. Part 1 explored the theme of water, while part 2 focused on soil fertility under organic vs. conventional farming systems. In part 3, we looked at how biodiversity is affected by farming. Now, let’s find out which farming system is best to combat climate change!

Climate protection

Farming plays a key role in protecting our climate.

On the one hand, agriculture is one of the biggest contributors to climate change. On the other hand, agriculture has the potential to not only be climate-neutral, but to stop climate change!

Let me explain.

One of the main greenhouse gases is carbon dioxide (CO2). And one of the main components of soil is carbon (C). Soil can both be a source of CO2 and it can store CO2 in the form of organic matter (humus).

The question then is: does the soil release more or less carbon dioxide than it stores? Or in other words, do our soils protect our climate or accelerate climate change? Both is possible, it all depends on the way in which soils are managed.

Comparing conventional & organic farming, which system is better at protecting our climate? Obviously, we cannot respond to this question without looking at soil fertility, once again.

CO2 stored or released?

In one of the previous posts of this series, we saw that under organic farming,

• the organic carbon content of the soil was 26% higher

• the aggregate stability of the soil was 15% higher

• and soil erosion was reduced by 22% as compared to conventional farming.

This already shows that organic farming has the potential to store more CO2 and revert climate change.

According to the study*, the carbon sequestration (or storage) rate was higher by 939 kg CO2 equivalents** per hectare and year under organic management. Basically, this means that the average organic farmland yearly stores 939 kg CO2 (or other greenhouse gases) per hectare more than conventional farmland does.

Nitrous oxide

Another greenhouse gas is nitrous oxide, a gas that is 300 times more potent as a greenhouse gas than CO2. Nitrous oxide is emitted into the atmosphere from fertilizers or manure that is applied to farmland. Emissions of nitrous oxide prove to be lower on organically managed farmland than on conventional farmland by 140 kg CO2 equivalents per hectare and year.

According to this data, organic farming performs better at protecting our climate.

Per hectare or per kilogram?

However, we need to differentiate whether these environmental effects are considered per hectare or per unit of produce (for example per kg of milk or per tonne of wheat). Since yields are generally lower (by around 25%) in organic agriculture, it uses more space to produce the same amount of food than conventional agriculture. Consequently, greenhouse gas emissions per area and per unit of produce lead to different results regarding agriculture’s climate efficiency.

This study concludes that total emissions per kg of milk from organic and conventional milk production are considered to be comparable.

Other studies that focused on the yield-scaled question came to the conclusion that organic farming has a worse net effect on climate change than conventional farming. How did they come to this conclusion? They calculated the additional land area that would need to be farmed to compensate for lower yields in organic farming.

The additional land that would need to be farmed would often be former forests or other natural habitats. And the conversion of forests to grassland or farmland has a more adverse effect on climate change than could be compensated through the enhanced soil carbon sequestration of organic farming.

In short: organic farming necessitates more land to produce the same amount of food than conventional farming. More land means cutting down more forests elsewhere, which ultimately means more greenhouse gas emissions.

Is organic worse for our climate?

According to these calculations, if we all went 100% organic, we would do more harm than good to our climate.

However, the key question then is: do we need to continue producing the same amount of food in the future (or even more)?

We have to consider that between 25% and 50% of all food produced in the world is wasted (for different reasons – both in developed and developing countries!).

Also, two-thirds of the grain produced in the EU is used to feed animals, not for direct human consumption. This high demand for animal products already is contributing to deforestation. See my article Reconsidering Animal vs. Plant-Based Diets for a more in-depth discussion of this.

In addition to that, there still is arable land that is not used for growing food (in Africa alone there are around 320 million hectares of fallow land).

There is enough land on our planet, the question is what we use it for.

Conclusion

To conclude, organic farming is better at protecting our climate when the area-scale is applied. However, if we apply the yield-scale, conventional farming is better for our climate.

Still, organic farming might be the only viable option for the future. Because: what’s the use a climate-friendly farming system if we risk to lose biodiversity (including pollinators!), soil fertility and clean water?

Organic farming can only serve to revert climate change if, at the same time, we eat less animal products, stop wasting food globally and use the arable land that is already available to us, without further deforestation.

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Since climate change already is a (felt) reality in our world, we’re going to look at the question of whether conventional or organic farming is better adapted to climate change in the next post. Stay tuned!

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*Sanders J, Hess J (eds) (2019) Leistungen des ökologischen Landbaus für Umwelt und Gesellschaft . Braunschweig: Johann Heinrich von Thünen-Institut, 364 p, Thünen Rep 65, DOI:10.3220/REP1547040572000

**CO2 equivalent – each greenhouse gas has a different global warming potential. For example, releasing 1 kg of methane (CH4) into the atmosphere is equivalent to releasing 25 kg of CO2. 1 kg of nitrous oxide (N2O) is equivalent to about 300 kg of CO2. To be able to compare figures more easily, the unit “CO2 equivalent” was introduced.