I'm a professor at U Michigan and lead a course on climate change problem solving. These articles often come from and contribute to the course.
By: Dr. Ricky Rood , 5:18 AM GMT on May 09, 2013
How Much Does It Cost: What Can I Do? (6)
This is the continuation of a series in response to the question, “What can I do about climate change?” Links to the previous entries are listed at the end.
Last week rather than taking the conventional view of looking at greenhouse gas emissions from the burning of fossil fuels, I presented an accounting of the emissions associated with agriculture. My primary points were that agriculture was a major emitter of greenhouse gases, and, therefore, the choices we make individually and collectively about what we eat have large environmental consequences.
I want to explore more the impact of agriculture, particularly livestock. First, however, I want to remind folks of the series on calculating budgets. Last summer I did a series where I compared the basic methods of climate science to keeping a budget – just like a checking and savings accounts. One of the entries in that series looked specifically at complexity. The idea being that despite the fact that maintaining a budget is a relatively simple matter of addition and subtraction, if you consider all of the ways we get and spend money, then it can become remarkably complex.
I implied the complexity of accounting for the greenhouse gas emissions of agriculture in the previous entry. The amount of emissions from the direct use of fossil fuels is relatively small. Big sources of emissions come from removing trees and changing forests to agricultural lands and soil management. Many aspects of soil management influence how much carbon and nitrogen is stored in the soil. There is also the need to consider greenhouse gases other than carbon dioxide: for example, methane associated with ruminates and solid waste from livestock and nitrous oxide associated with fertilizer. Emissions also depend on:
- what crops are grown and what animals are raised
- agricultural practice, for example, whether the land is plowed or no-till methods are used
- policy, for example, renewable energy policy provides incentives and disincentives on what to grow
- biological processes that are different from field to field, region to region, year to year, and that are not highly quantified
The calculation of the budget of emissions from agriculture is a difficult problem. We can say with certainty the emissions are large and they change based on many factors. We can also say that the impact of agriculture on the environment is more far reaching than climate change. Anecdotally, most people think of the impacts of pesticides and herbicides, the issues of genetically modified organisms, soil erosion and water quality before they think of how agriculture and climate change play together. Agriculture is also a major focus of those who think about sustainability.
I ended the previous entry with a relatively weak statement that what we chose to eat or not eat does make a difference. I stated that at the top of the list, perhaps, the easiest decision is to eat less meat. The issue of eating meat, of course, steps into a set of the more controversial subjects of our society. For example, there are the issues of personal choice and intrusion into individual's lives. Also, there are those who place high value on the ethics of raising and slaughtering animals. There is no doubt, however, that livestock production uses immense resources.
The source of much of the material in my previous entry was Livestock’s Long Shadow a 2006 publication of the Food and Agriculture Organization of the United Nations. In that report they conclude:
“Livestock’s contribution to environmental problems is on a massive scale and its potential contribution to their solution is equally large. The impact is so significant that it needs to be addressed with urgency. Major reduction in impact could be achieved at reasonable cost.”
As strong as this statement is, there is a school of thought that Livestock’s Long Shadow is a significant underestimation of the emissions due to livestock. Most notably is an analysis by Robert Goodland and Jeff Anhang, Livestock and Climate Change, which does a different accounting of the budget of emissions of greenhouse gases. In Livestock and Climate Change it is maintained that there is significant undercounting and misallocation in the United Nations budget calculation. A point that is particularly important is that the proliferation of livestock production is human-made just as much as any building, road or power plant. Therefore, for example, the carbon dioxide of respiration of the animals needs to be considered in the budget calculation. Taking all of the budget changes in Livestock and Climate Change, the conclusion is that livestock is responsible for 51 percent of the total emissions. With this number, a far larger intervention is needed than “eat less meat.”
In December 2009, I took a group of students to the 15th Conference of the Parties in Copenhagen. When I got off the subway at the conference center, there were two loud groups of advocates. One was People for the Ethical Treatment of Animals, who had gone around Copenhagen and placed markers on utility poles and in trees where sea level would be if the Greenland ice sheet melted. Another group claimed that if we were all vegetarian, then we could reduce global warming by 70 percent.
The numbers in Livestock and Climate Change follow from a well-reasoned argument in the calculation of the budget of the emissions due to livestock. However, they are not without controversy. This controversy can be found in a number of places on the web: Columbia Journalism Review and Lifting Livestock's Long Shadow, Nature Climate Change and Measuring Livestock's Long Shadow, NYTimes. At the center of the controversy is another accounting of the impact of livestock, Cleaning the Air: Livestock's Contribution to Climate Change by Maurice Pitesky and others. This paper takes a vastly different accounting and concludes that impact of livestock is much smaller than in the United Nations Report, Livestock’s Long Shadow. An interesting aspect of its argument is that “The fact that land-use changes associated with livestock (i.e., forested land converted to pasture or cropland used for feed production) are a significant source of anthropogenic GHGs in Latin America and other parts of the developing world is apparent. However, it is likely that any kind of land-use change from the original forestland will lead to great increases in global warming.” The argument being that development in countries with growing population will lead to deforestation. Their argument is carried further “The United States and most other developed countries have not experienced significant land-use change practices around livestock production within the last few decades. Instead, over the last 25 years forestland has increased by approximately 25 percent in the United States and livestock production has been intensified (concentrated geographically), thus reducing its geographical footprint.”
The line of reasoning in Cleaning the Air: Livestock's Contribution to Climate Change contributes to the argument that concentration into highly efficient, mass producing farms is a more practical way forward than reducing consumption (Livestock production and the global environment: Consume less or produce better?, by Henning Steinfeld and Pierre Gerber).
In this food niche of strategies to mitigate climate change, we see the same arguments emerge as in the discussion of fossil fuels. We could be more efficient in our use of resources. With efficiency, however, in the face of a growing population and growing consumption, we are still faced with a growth of emissions of greenhouse gases. Therefore, if climate-change and broader environmental issues are given priority, then we must consume less of those products that are responsible for our largest greenhouse emissions. We can conceive of sources of renewable energy that are free of carbon dioxide emissions. However, it is more difficult to imagine how we raise livestock without the methane and nitrous oxide emissions, and these greenhouse gases cannot be dismissed.
My original list topper on diet was eat less meat. If we take the high emissions scenario as correct, then a climate priority calls for an intervention into our dietary practices that is comparable to the intervention required for reducing fossil fuels. This is a change in diet that I assert will be more difficult than the change in our energy system. Therefore, back to the original question, “What can I do about climate change?” – eat (a lot) less meat. Vegetarianism is good for the planet. This from a man who does eat a lot less meat than he used to, but has been, I maintain, overidentified with BBQ.
Some dietary resources: I have not checked these out too closely!
Environmental Working Group: Meat Eaters Guide (I do like this group’s approach to things.)
Human Media: The Diet-Climate Connection
Previous Entries in the Series
Setting Up the Discussion Deciding to do something, definition of mitigation and adaptation, and a cost-benefit anchored framework for thinking about mitigation
Smoking, Marriage and Climate Behavioral changes and peer pressure
Organizing and Growing Individual Efforts A little detail on efficiency and thinking about how individuals can have more impact than just that of a single person
The Complete List Eight categories of things we can do to reduce greenhouse gases
We Are What We Eat Counting agriculture and its emissions of greenhouse gases
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