A Serial Blind-Spot For Organic Advocates

Researchers affiliated with the Institute of Organic Agriculture in Switzerland and the Institute of Agricultural Sciences in Germany published a meta-study in which they conclude that organic farming methods lead to higher rates of carbon sequestration in soils.  This work was well done and published in a well respected journal, PNAS.  Unfortunately the ramifications of the paper are being badly misinterpreted by environmental and food bloggers who are organic advocates.  The scientific authors make no claim that their analysis is a full, net carbon footprint measurement, but it is being interpreted that way by others.  Building up soil carbon is a very good thing to do, and organic methods were the state-of-the-art method for doing that from around the 1920s to the 1960s.  However there are newer and better ways to improve soil quality on farms, and they don't have the huge carbon footprint problem that is common in organic - emissions of the potent greenhouse gases methane and nitrous oxide which have 21 and 295 times as much greenhouse gas effect as carbon dioxide respectively.

All forms of farming including organic can lead to soil emissions of these gases, particularly the nitrous oxide.  Those are best managed by the new farming methods I mentioned above.  The issue that is problematic for organic are emissions of those gases associated with composting.  To borrow a line from Al Gore - this is "an inconvenient truth" about organic.  This inconvenient truth is that any significant adoption of the compost-use feature of organic farming would be an environmental disaster.


I have written about this a few times before, but because of the misinterpretation of this study I want to reiterate that this is a clear-cut issue where organic is problematic. The common failure to recognize this very important issue leads to misguided policies and people believing that they are doing something very "green" when in fact the opposite is true.

I have done quite a bit of carbon footprint analysis regarding agriculture over the years as part of my paying job as a consultant.  That has given me the opportunity to read extensively from the scientific literature on this topic and on life cycle assessments (LCAs) in general.  From that work I came across a body of literature concerning greenhouse gas emissions during composting (I'll put a list of papers at the end of the post).  The goal of composting is to keep things aerobic (with oxygen), but inevitably, even in the best managed composts there are micro-sites that are anaerobic (no oxygen) and under those conditions some microbes generate methane or nitrous oxide.  The numbers are not small.  In one typical study of this type the carbon footprint of the finished compost ranged from 1,769 to 2,167 pounds of CO2 equivalents per ton.  Since compost is applied at rates such as 4 to 10 tons per acre, that means 7-22,000 lbs of CO2 equivalents for each organic acre.  The middle of that range is like driving a 25 mpg car 13,982 miles or fertilizing 12.9 acres of corn at 200 lbs of synthetic nitrogen/acre.  It would be equivalent to growing, handling and transporting 9,641 lbs of bananas from Costa Rica to Germany.  This is a major reason that it is a good thing that organic remains such a small part of agriculture.

The Serial Blindspot

The false assertion that organic is better from a climate change perspective keeps coming up over and over again.  In this case it was through misinterpretation of a good paper.  The more problematic examples have been claims from generally credible organic groups - the US's Rodale Institute and the UK's Soil Association.  Each organization has published white papers claiming that organic is a solution to climate change.  In both analyses, the authors completely ignore the issue of greenhouse gas emissions from composting as well as other parts of organic farming (e.g. there are even more emissions once the compost or manure is incorporated in the field).  I've corresponded with the authors in both cases and they have not been able to dispute my points.

Why Does This Matter?

So, what sort of policy and thinking problems arise from the promotion of this false impression about organic?  One example would be the US government spending money to encourage more farmers to adopt organic practices.  Another would be the many consumers who spend more believing that they are doing the green thing by buying organic (There are also several other reasons that is not true).  Another would be other consumers who unnecessarily feel guilty because the don't want to spend so much.

I think the most absurd example is San Francisco's much touted food waste recycling program .  Sending food waste to a landfill is definitely bad, but the best solution is for people to grind it up in their disposal, send it into the sewage system, and for the treatment plant to convert it to renewable, carbon-neutral energy using an anaerobic digester (most advanced sewage treatment districts do this now).  But perhaps the San Francisco sewage system can't handle that volume.  In any case, what they do is to drive heavy trucks up and down the famously steep hills of the city collecting the scraps.  Then they drive the heavy loads 50 miles to a composting facility in Vacaville.  There they generate the trace gases in the process I've described above.  Then they load the heavy compost back into trucks and haul it 50 to 100 miles to organic vineyards who then claim to be doing something sustainable.  That is pretty absurd.

I'm sure this won't be the last time that people will make unfounded climate change mitigation claims for organic.  It won't be the last time I try to explain why they are not true.

You are welcome to comment here and/or to email me at savage.sd@gmail.com   I tweet a bit @grapedoc.  Organic farm image from wikimedia commons.  Composting in the UK image also from wikimedia commons.

References:

•Hao, X., Chang, C., Larney, J., Travis, G. 2001. Greenhouse gas emissions during cattle feedlot manure composting. Journal of Environmental Quality 30:376-386.

•Osada, T., Kuroda, K., Yonaga, M. 2000 Determination of nitrous oxide, methane, and ammonia emissions from swine waste composting process.  Journal of material cycles and waste management 1:51-56

•Hellebrand, H.1998. Emission of nitrous oxide and other trace gases during composting of grass and green waste. Agric. EngngRes. 69:365-375 

•Sommer, S., Holler, H.2000. Emission of greenhouse gases during composting of deep litter from pig production – effect of straw content. The Journal of Agricultural Science 134_327-335

•Hao, X., Chang, C., Larney, F. 2004. Carbon, nitrogen balances and greenhouse gas emission during cattle feedlot manure composting.  Journal of Environmental Quality 33:37-44

•Jackel, U., Thummes, K, Kampfer, P. 2005. Thermophilic methane production and oxidation in compost. FEMS Microbiology Ecology 52:175-184. (looking for microbes which might help reduce the methane emissions from composting)

•Hellmann, B., Zelles, L., Palojarvi,A, Bai, Q. 1997.  Emission of climate-relevant trace gases and succession of microbial communities during open-windrow composting.  Applied and Environmental Microbiol 63:1011-1018

A Modest Proposal About How To Do GMO Food Labeling Right

Should food with ingredients from genetically engineered crops - "GMOs" - be labeled?  Many argue that consumers have a "right to know" about this.  Ok, if the real reason for labeling is to provide consumers with knowledge, then the label should read:

"Contains ingredients from biotech enhanced crops approved by the USDA, FDA and EPA"

That would tell people what is unique about these crops.  Humans have been genetically modifying crops for centuries using a variety of methods.  The difference for genetically engineered crops is that they must be fully characterized and tested in order to gain approval from three different regulatory agencies - the USDA, the EPA and the FDA (there is a description of this process below if you are interested).  Crops modified in other ways including those generated by conventional breeding, mutation breeding or "wide crosses" or hybrids or doubled haploids don't have to be tested or approved at all.  The clear, international scientific consensus is that genetic engineering involves no unusual risk relative to all the other methods of genetic modification, but this testing was instituted out of an abundance of caution.  Thus, any label should let consumers know about this extra level of scrutiny conducted for their benefit.

Precedents

We have a precedent for a positive, official label designed to communicate government oversight. This is the federally regulated "USDA Organic" label that signifies that the agency governs the certification process for that food.  The biotech food labeling should be of this same affirmative nature because of the extraordinary review from three agencies.  We also have warning labels for real risks like certain allergens and for trans-fats, but that kind of labeling is inappropriate for genetically engineered crops.  On the contrary, there are hundreds of peer reviewed scientific studies that looked for and failed to find health issues associated with these foods.

Let's Really Make It About Knowledge

Also, if we label genetically engineered foods, we should accompany that with supporting educational resources.  We have some experience as a country about what happens if you label but don't educate. Back in 1994, Congress passed the "Nutrition Labeling and Education Act" that lead to that list of nutrient contents you see on food packages.  The lawmakers never followed through to provide the funding for the education part (imagine that!)  So the law effectively became the "Nutrition Labeling in a Vacuum Act" and many consumers get little benefit from the labels.  Let's not repeat that mistake with a "GMO Labeling in a Vacuum" law. 

Accompanying the label I have described, there should be a URL or a code stamp to take you to web sites that explain how these crops are developed, how they have been evaluated, and also about some of their advantages. The site could talk about how:

• Herbicide resistance traits help farmers to enable no-till farming which has huge environmental advantages.  
• Insect resistant crops make farming easier and safer by eliminating the need for many insecticide sprays.  
• Bt Cotton is helping small-scale farmers in India escape malnutrition.  
• Drought tolerance and insect resistance traits reduce the threat of carcinogenic mycotoxin contamination in the food supply. 

Congress could even fund an educational program to provide basic nutrition education which should have started 18 years ago. 

If some politician will introduce a bill to require labeling of the type I have described and include guaranteed funding for real education, they could get the enthusiastic support of the scientific community.  

Would my labeling suggestion satisfy the groups that have been promoting "GMO labeling?"  Probably not. There is pretty strong evidence that their goal is not really about what consumers would "know."  It seems more likely that it is about wanting consumers to be afraid and thus to buy more of the organic, certified non-GMO, or under-regulated supplements they sell (look who provided the money to push prop 37 in California).  The clue is the typical imagery used by these labeling promoters and their allies.  It usually involves the meme of a large, scary looking hypodermic needle filled with a suspicious, liquid being injected into something like a ripe tomato.  

That image bears absolutely no relationship to how plants are genetically engineered.  It is a transparent attempt to frighten people.  Thus, if the labeling were to actually let consumers know enough not to be afraid, it wouldn't accomplish the financial goals of many of the groups pushing labeling. It might even reduce their sales.

I salute my fellow Californians for voting down Proposition 37, a deeply flawed GMO labeling initiative which would have been a consumer knowledge disaster for the financial benefit of certain folks who really don't deserve it.  As a scientist and someone who cares deeply about food, I could endorse a food labeling law like the one in my modest proposal.

You are welcome to comment here and/or to email me a savage.sd@gmail.com.  I tweet from time to time @grapedoc.  Shopping image from Anthony Albright. Code stamp image from Allprostamps.com.  Tomato image from Global Research Canada

Additional Background About How These Crops Are Regulated

For those that are interested here is some background.  GMO crops, those that have been modified using the tools of genetic engineering, go through a degree of composition and safety testing which has never been required for other means of improving crops - even methods such as mutation breeding or wide crosses which have far more potential for undesired effects.  These new crop varieties are scrutinized by no less than three federal regulatory agencies under a system called "The Coordinated Framework" that was hammered out in the 1980s and 1990s well before any GMO crops were commercialized.  Historically most regulation of industries has been instituted after there has been a problem.  GMO foods are rather unique in that the regulations were designed before there was any commercialization and in the absence of any problematic events.

How Does The Regulation Work?

The USDA scrutinizes any potential for the crop to be a "plant pest risk" and any sort of gene transfer issue for other crops or weeds.  The EPA scrutinizes any pesticide-related issues such as the Bt-based insect resistance traits or the herbicides that would be used on herbicide tolerant crops.  The FDA scrutinizes the data that the companies submit to demonstrate that their new varieties are functionally identical to non-modified versions of the crop. They don't have specific requirements because each crop and modification would be unique in terms of what matters. Still, that does not mean what is often alleged that there is "no required testing."  The submission is technically voluntary, but all biotech crop developers have always submitted data to the FDA.  Again, new crop varieties from all other mechanisms of genetic modification have no testing requirements at all, so if there is any testing it is on a purely voluntary basis. "GMO crops" are unique in that they must be tested and approved.

With all this analysis of GMO crops, it is should not be surprising that even though this technology has been adopted for billions of acres of crop production over 16 years, there have been no legitimate health or environmental problems, and rather a great many benefits.