Recent headlines have purported that organic farming is worse for the climate than conventional farming. This claim is based on a scientific study recently published in the journal Nature, titled “Assessing the Efficiency of Changes in Land Use for Mitigating Climate Change” (Timothy D. Searchinger, Stefan Wirsenius, Tim Beringer & Patrice Dumas).

The study introduced a new method for calculating greenhouse gas emissions from agricultural production that includes the opportunity cost of land converted from natural habitat to farmland.

We commend the study authors for working to bring a greater level of precision to measuring greenhouse gas emissions from anthropogenic activities. The science in the paper is sound, and the study was intended to present a new model using existing data and not intended to demonize organic agriculture. However, we can’t derive the conclusion that organic is worse for the environment from its findings.

Key Issues

The study compares organic and conventional production systems growing two crops (winter wheat and peas) in Sweden. The comparison is derived from yield and input data reported by the Swedish Board of Agriculture from 2013-2015. It is impossible and irresponsible to extrapolate a global phenomenon based on two crops grown in a single country over just three years.

The study presents a graph that shows greater carbon sequestration benefits in conventional versus organic systems. However, the high degree of variation in the data used (as indicated by large error bars on the graph) suggests that differences between organic and conventional systems may not be statistically significant. More data should be included and analyzed before conclusions are drawn. The study duration is also too short to measure long-term effects.

Source: Assessing the Efficiency of Changes in Land Use for Mitigating Climate Change. Timothy D. Searchinger, Stefan Wirsenius, Tim Beringer & Patrice Dumas.

Taking the Long View

Importantly, the Searchinger et al piece ignores below-ground biological processes and interactions between plants and microbes that are the true building blocks of carbon sequestration.

The study does not take into account the fact that organic systems promote soil biological diversity, which results in greater stores of carbon and nitrogen in the soil.

Long-term, more carbon is stored in the soil in organic systems, and the need for external inputs is reduced.  Short-term comparisons like that from the Searchinger et al study do not take into account the long-term benefit of organic farm production. 

Download “Regenerative Organic Agriculture and Climate Change,” a whitepaper, here.

Lessons from the Farming Systems Trial

Carbon Sequestration

The best place to store carbon long-term is in the soil. 38 years of research at the Rodale Institute Farming Systems Trial has proven that organic farming systems store more carbon in the soil and deeper in the soil than conventional farming systems.

rodale fst soil graph
Soil organic matter data collected from the Farming Systems Trial comparing a conventional system, manure-based organic system, and legume-based organic system.

Emissions

The Searchinger et al study acknowledges thatwhen one considers inputs fertilizer-intensive conventional methods generate more greenhouse emissions than organic, which do not use synthetic fertilizers.

Their finding that organic creates more emissions comes from an interpretation that lower yields from organic would require more land clearing, and that that deforestation would have a more devastating environmental impact than fertilizer use.

The flaw here (before we tackle the issue of yields) is in analyzing just one dimension of impact and assuming that we need ever-increasing yields of the same crops we grow now in order to feed the world.

Greenhouse gas emissions are just one “ecosystem service,” and we can’t reduce human and environmental health to just one measure.

Conventional farming practices also contribute to acute poisonings and health risks due to pesticides; groundwater and surface water contamination; loss of biodiversity including pollinators, fisheries, and wildlife; and government expenditures for cleanup. They can degrade soil health and create indirect environmental and health care costs that are difficult to quantify.

As for yields, current food production has been shown to be nutritionally inadequate. Rather than focusing exclusively on yields, we’ll need to turn our attention to nutrient-dense foods in order to feed a growing global population.

Yields

The Farming Systems Trial has also shown no statistically significant difference in yields between organic and conventional systems. In general, during years of adequate rainfall, there is no statistically significant difference in yields between organic and conventional systems. However, in years of extreme weather such as drought or flooding, and even years with less extreme weather like low rainfall, the organic systems out-yield conventional up to 40%.

corn no-till graphic
2016 yields from the Farming Systems Trial. The organic manure system not only outperformed conventional but set a record for our county.

Take wheat, one of the crops analyzed in the Searchinger et al study. From 2004 to 2013, there were eight years in which we grew wheat in both organic and conventional systems at FST. Over that time there was no yield difference between the organic (manure-based) system and the conventional system, and in 2010 the organic tilled system out-yielded the conventional no-till system by a significant measure. Both systems did outperform our legume-based organic system.

Our data showing the competitiveness of organic yields has been gathered over the course of decades. Data collected over just two or three seasons is inadequate to truly assess and make widespread claims about differences in farming systems. 

Where We Go From Here

The Searchinger et al study used a limited data set but a good calculator. Let’s contribute more data. If other farmers and researchers input their datafrom different parts of the world, growing different crops, and over longer time periodswe might be able to verify the true impact of organic production. 

Dr. Andrew Smith is Chief Scientist at Rodale Institute.

10 thoughts on “Is Organic Farming Really Worse for the Climate? A Response

  1. I have to admit that I got confused after reading just the first four paragraphs of the article. Perhaps someone will be willing to explain it to me. In the third paragraph just before the KEY ISSUES it says, “We commend the study authors for working to bring a greater level of precision to measuring greenhouse gas emissions from anthropogenic activities. The science in the paper is sound, …” Then in the KEY ISSUES is says, “It is impossible and irresponsible to extrapolate a global phenomenon based on two crops grown in a single country over just three years.” and “However, the high degree of variation in the data used (as indicated by large error bars on the graph) suggests that differences between organic and conventional systems may not be statistically significant.” So, if those two things are true, then how can the science in the paper be “sound”? Is there a different meaning for “sound” that I am not aware of. Could someone please explain this to a non-scientist.

  2. Hi Linda,
    It’s certainly a complex and confusing issue. The paper itself is sound and the comparison of organic and conventional was just one piece of it. The problem was in how the paper was interpreted and publicized (as a definitive statement on organic’s impact). Here’s a response to your comment from Dr. Smith:

    “The study authors created a sound method to determine carbon sequestration. They used existing data to test it. But the paper was about a lot more than a comparison of organic and conventional. It looked at different diets – vegan, vegetarian, pescatarian, baseline standard – and it looked at different grazing practices in Brazil versus growing soybean in Brazil. It took a small amount of data from Sweden on organic and conventional wheat and peas, but all of these data are really just a snapshot of the bigger picture. The organic versus conventional piece in the paper was not really even highlighted.”

  3. The following is “food for thought;” to obtain better thought we need better nutrition to feed our brains; to get better food for our brains we need “better” more nutrient rich foods to eat; to get more nutrient rich food we need to grow them using regenerative agricultural techniques.

    We need to develop new standards for measuring yields. Volume yields mean nothing if there is not adequate nutrition available (the main reason for consuming food). The standard for measuring corn yield is 56 lbs. per bushel volume. Some corn may weigh much less per bushel, some may weigh much more; the most dense ever measured was about 64 lbs. / bushel. This was grown with regenerative/biological methods and equated to about 400 bushels per acre.
    Assuming that the higher densities are due to increased mineral content and better secondary metabolite compounds, and that these are better for us nutritionally, instead of just starch and sugars; which would you rather eat or feed to animals? Which s going to be more cost efficient to grow, to harvest, to store, to purchase, to feed, to eat?
    We need a standard that measures not just weight per bushel but nutrients per bushel as well. Investigate Bionutrient Food Association at to see how a new definition and standard for food nutrient measurement is being developed.
    If we can produce food that is much more nutrient rich than we have in effect increased the amount of currently farmed available farmland, by potentially 25 to 50 %, with out ever having to destroy any remaining wild / natural ecosystem areas to grow real food!!

  4. Personally, I don’t have respect for a lot of our “modern” science. It never truly tackles the complicated process involved in anything anymore. There are a lot of factors involved in this, and I personally don’t worry about CO2 but pollution, soil vitality and erosion more. However, mono-culture fields aren’t really sustainable and encourage lower yields and soil erosion and depletion. Permaculture, simply by virtue of not wasting space, would have higher yields and less erosion. But it is not suitable for large scale agribusinesses. Even beyond the harm extracting, and using, the materials used for chemical farming; it doesn’t supply any real benefits other than making it easy for large industrialized farming methods that can only produce more in bulk (but not in quality) than the same area tended to by a group of small farmers. Just the opinion of an old country boy who also doesn’t believe the science of global warming is valid since one of its’ main parameters is to ignore anything outside of man-made causes. I think the ocean belching more CO2 (from an event some 700 years previous) in a single episode than we have ever produced, and that big ball of fire in the sky which is going into a grand solar minimum (Ice Age: More than just a cool cartoon) might have a bit of input into it all as well. But Mother Nature has no say in the hysterics that is Climate Change. The last great Ponzi Scheme where science is firmly rooted in politics. As usual.

    1. Deniers have had their chance to make their case. They’ve lost. Please get out of the way. Your comments contribute nothing to the discussion.

    2. So you’re into some science but not climate science? Science may not yet know all, but climate change has been established and accepted​. Also, I have seen other climate change accepters and deniers getting a little too comfortable with the approaching solar minimum. There were global droughts (Irish potato blight / famine ring a bell?) during the Little Ice Age that were, at the very least, partly attributable to the solar minimum. Weakened solar radiation means less rain. Solar radiation causes evaporation which creates clouds and so on. Just because the temperatures are warmer due to elevated greenhouse gas concentrations, that won’t do us any favors when it comes to precipitation. In fact, CO2 is less water soluble in warmer temperatures. Hell, increased emissions and temperatures might actually even repel rain systems, creating more chaos and imbalance.
      So the solar minimum will not cancel out the threat of global warming. That is a dangerous over-simplification that assumes that elevated temperatures are the main hazard of climate change. Irregular rainfall via flooding or droughts (which includes increased wildfire risk) is, and has been, the greatest threat to human societies since the days of the Mayan Empire. If anything, the approaching solar minimum could make our problems a whole lot worse.

  5. Thanks Dan for your comments. I couldn’t agree more. This is an important area of research for Rodale Institute right now, especially with our Vegetable Systems Trial, to grow more nutrient dense food and solve food insecurity issues. We believe food is medicine and how you grow foods impacts the nutritional quality of food and therefore human health. We aim to put sound science behind that claim.

  6. At more than 5,000′ in elevation in south-central Idaho we are lucky to get 4.5 tons of high protein organic alfalfa per acre per annum. One of our neighbors, using a seed drill and other no-till practices, saw a verified 6+ tons (dry biomass) per acre yield from a 15-species cover crop on non-organic land. This is consistent with another similar trial in south-western Idaho (6.25 tons of dry biomass from a multi-species cover crop per acre) and the results that Gabe Brown has demonstrated with all sorts of multi-species seed mix cover crops. In Gabe’s case, he has tracked soil organic matter from less than 2% to more than 8%, principally by leaving, as I recall, at least a third and perhaps as much as 50% of the above-surface organic material produced each year for decomposition and incorporation in the soil. To grow food, you need water, and the verified water-holding capacity statistics of Gabe’s best soil are phenomenal. As his neighbor’s conventionally farmed, dead soil, is depleted and erodes, Gabe’s soil represents a a vast water reservoir and defense against runoff, flooding and soil transport. In addition, we can winter feed livestock on the unharvested biomass, including radishes, beets for energy, various high-protein legumes, etc., making it unnecessary to swath, rake, bale, stack, then unstack and load (on a flatbed trailer pulled by a tractor) to feed. Think of it. Way less petrochemical input, way less capitalized equipment cost, way less labor cost. Just put livestock in a pie-shaped electric-fenced slice of a pivot field and move every other day.

    It may be difficult to quantify in a meaningful way the impacts of, say, glyphosate, on human health, but it should be relatively straightforward to normalize for nutrient density in crops.

    We have farmers here in Idaho that now get astounding bushel yields of organic corn per acre. I agree with Dr. Smith, in that short-term studies do not capture the potential for soil regeneration. It’s taken us many decades to destroy our soils in the United States. It shouldn’t be a surprise that it will take some time to restore them.

  7. Did the study take into account the CO2 emissions from the chemical plants that manufacture the pesticides and herbicides that are applied to fields in a conventional or no-till farming system?

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