Life cycle analysis in animal agriculture

In Reducing the environmental impact of farming, I talked about Nathan Pelliter’s work on Agricultural Life Cycle Analysis as a way to evaluate which farming methods have the least environmental impact. While the ideas apply to any type of farming (or really to the production of anything), his main work is actually on animal agriculture.

The return on investment of most types of animal agriculture is small compared to that of plant agriculture. For example, cattle require about 6 pounds of feed to produce 1 pound of muscle. All of the water, fertilizer, and pesticides required to grow 1 pound of plant material is thus multiplied by 6 to produce 1 pound of beef. Granted, it isn’t quite that simple, as parts of plants that aren’t used for human food can be fed to animals, but the point holds, even in organic systems.

Reducing the environmental impact of farming

Atmospheric concentrations of greenhouse gasses are rising, but reducing them isn’t as simple as taking cars off the road. A significant part of the problem rests is agriculture. What is it about agriculture that is such a problem and how can we develop changes that will have the most benefit?

Agricultural Life Cycle Analysis is a useful tool in collecting information and making decisions. LCAs take every input and every output into consideration including difficult to consider ouputs like greenhouse gas emissions.

Nathan Pelletier from Dalhouse Uni in Nova Scotia presented his work on ag LCAs at Iowa State recently. He explains that actually conducting LCAs can be difficult. First, we need to define the scope of the analysis. For example, if we consider milk production, we should likely include the cow herself, food, water, and waste. We probably should include all of the inputs and outputs associated with feed production and transportation. We might include the inputs and outputs of pasteurizing and transporting the milk. Also difficult is actually quantifying all of the inputs and outputs to air, soil, and water. Finally, it is difficult to complete a meaningful impact assessment including the identification of “hotspots” or most negative impacts. Despite the difficulties, LCAs are worth the effort. Nathan reminds us that agriculture produces 1/3 of global warming emissions. The demand for food will will double by 2050, so we need to half the impact to continue a constant level of damage.

After the flood

As flood waters are receding or moving downriver, I have been wondering what is in the water. The health and environmental risks now faced by the flooded areas and beyond were ignored for a while, but seem to be coming out – notedly in a few AP and NPR stories. The CDC has an entire website devoted to health after a flood. The flooding all over Iowa is extensively covered by the Des Moines Register, but the one article on health issues is severely lacking, focusing on injuries instead of infection. Many ignore the environmental consequences.
Fecal bacteria from manure lagoons and sewers will reside in mud left behind by the floodwaters. People cleaning up debris are at risk of tetanus and other infections in scrapes and scratches. Residual water will be a breeding ground for mosquitoes that may carry West Nile and other viruses. And, of course, the mold will grow.
Topsoil has been washed away. Pre-emergent herbicides may have effects from from their intended fields. Nitrogen from fertilized fields and animal waste will flow downstream, likely not causing problems until reaching the Gulf (this has been covered by some news outlets but is typiclly and incorrectly blamed on ethanol, more on that in another post).
All this on top of the structural damage and destruction of public and private property…
I’m upset about my own field – but am thankful that this is the only way I’ve been affected by the floods.

Colony Collapse Disorder

Colony Collapse Disorder has been in and out of the media since 2006. With conspiracy theories and non-science abounding, it can be hard to separate truth from fiction.

Dr. Diana Cox Foster of Penn State spoke at Iowa State about her work with CCD. She has been studying bees for 20 years and heads a diverse team of researchers working to solve the mystery. She said that there there are quite a few “theories” that her team disagrees with.

In particular, she said that CCD is not caused by the rapture or the Russians. She puts cell phones and genetically engineered crops in the same category, choosing instead to focus on legitimate leads. She says that there are many reasons why their group is not looking into these as possible causes, but one reason sticks out: some Amish and organic beekeepers whose hives are isolated from genetically engineered crops, many pesticides, and cell phones in the case of the Amish have experienced CCD, while some conventional beekeepers have not.

In other words, there isn’t a common thread connecting colonies that have collapsed.

Despite the fact that scientists like Dr. Cox Foster have spoken on the lack of legitimacy of these theories, people continue to write about them, such as this example from the always creative Global Research. I won’t pick the article apart due to time constraints, but wanted to show the range of views. A lot of mainstream articles have less extreme views, but few if any make an effort to debunk the incorrect theories. Instead, they reinforce them! Karl over at Inoculated Mind has a nice post summarizing some issues with the cell phone and GMO theories that’s over a year old. If only the reporters would research as he did.

There is abundant evidence that the Bt protein Cry1Ab doesn’t affect non-target insects. A meta-analysis from Jan 2008 of 25 independent studies found “that Bt Cry proteins used in genetically modified crops commercialized for control of lepidopteran and coleopteran pests do not negatively affect the survival of either honey bee larvae or adults in laboratory settings.” A meta-analysis from May 2008 of a public database found no significant effect on type or number of arthropods in Bt and non-Bt crops. They did find, as have many others, that various types of insecticides decreases the type and number of arthropods.

A quick lit search did come up with a June 2008 study that showed decreased learning ability in bees that were force fed syrup containing very high concentrations of Bt that are not found in the field. This data might indicate the need for more research on bee physiology, but doesn’t mean that Bt isn’t safe for bees in the field.

Now that we know what it’s not, I’ll share with you what Dr. Cox Foster thinks are the most likely causes and solutions…

Speaking for science

Rachel Carson was undoubtedly a force for good in the 1960s. She singlehandedly started the environmental movement by calling attention to the dangers of unregulated pesticide use. As a graduate of the University of Maryland College Park, I especially appreciate Carson’s work in the Chesapeake Bay.
Kate Neville, in The Science Creative Quarterly, calls for scientists today to do as Rachel Carson did. She enthusiastically concludes:

We should take from Rachel Carson the hope that her actions conveyed: that great change can come through research, that people do want to know more, and that narrative can bridge the gap. We need not all take on a public role to engage in this process: Carson’s influence came from her ability to synthesize work across many fields, which relied on the willingness of many researchers to take the time and effort to share their findings with her, and explain the significance and the debates. We must support our public intellectuals – question their conclusions, but champion their causes; critique their claims, but provide them with alternative information. We need to communicate our research more clearly, participate in dialogue and explanation, and engage with the issues of our time in collaborative, constructive, critical, and public ways. We have the potential to effect great change, even in the most improbable of cases, and even on the most intractable of problems.

I couldn’t agree more. That’s why I’m blogging, after all. I share Kate’s optimism, believing that the best way to make our world better is through new collaborations and communication that defies traditional boundaries.
Unfortunately, it seems that the movement started by Rachel Carson has forgotten the science their mentor championed and succumbed to pessimism. A few weeks ago, I flipped through Courage for the Earth: Writers, Scientists, and Activists Celebrate the Life and Writing of Rachel Carson. Many of the essays are appropriate, but some go too far, essentially saying that we should stop many types of research in medicine and agriculture.
Rachel Carson, herself a scientist, conducted a a cost-benefit analysis. She saw that the costs of pesticide overuse and industrial pollution outweighed the benefits, and acted accordingly. I don’t think we can predict what she would think about therapeutic cloning, genetic engineering, or many other technologies that have been developed since she passed. I do think she would have considered carefully, educating herself on the ramifications each would have on ourselves and our natural world.