One part, albeit a small part, of climate change discussions and ideas for reducing human impacts on climate, relates to food consumption choices. These discussions, particularly discussions about the how consumption of meat increases green house gases (GHGs) and how great an impact a reduction in consuming meat will have on the emission of GHGs, motivated me to explain why I made my choice, and to research further the current state of science in this area.
But a full review of the current science on the total green house effects of meat production, the impact of reducing meat consumption and the factors inhibiting action being taken (which largely lie in the realms of political and social science) is beyond a blog post. I intend to complete my reasearch in the form of a fully referenced journal article, with the hope of having it published.
I became a vegetarian about 2 years ago, and vegan about 1 year ago.
The pretence for making this decision was my growing concern about climate change and the destruction of environment.
It is proved (in so far as any scientist can prove how complicated natural systems work and how those systems are affected by various factors with 100% confidence) that the intensive agricultural farming of livestock for human consumption results in significant tracts of land being cleared of native vegetation which, with the production of animal products itself, causes GHGs to be emitted. signatories to the Kyoto protocol are required to monitor these emissions, amongst emissions from other industries. Australia’s most recent report fulfilling this obligation is here.
Vegetation uses carbon dioxide (CO2) as ‘food’ in the process of photosynthesis. Therefore, the clearing of land for agricultural purposes (or any other financial or political use for that matter) results in a reduction of the earth’s ability to absorb this greenhouse gas, putting pressure on other carbon sinks to absorb more carbon dioxide. As there is a limit to the rate vegetation can absorb CO2 (which was recently reviewed in an article in the journal Nature, here), there will ultimately be a build up of CO2 in the atmosphere where the rate of output is greater than the rate of absorption.
Even when livestock is fed with grain or corn, usually whilst held in small bays within a farm shed and using less land, CO2 emissions are still created in the energy used to produce and transport that feed to the farm, as well as in the construction, maintenance, powering etc of the sheds.
This is not to say that growing of fruit and vegetables do not have their own carbon footprint in their methods of commercial production, but it does have a significantly smaller GHG footprint in these particular parts of the agricultural process.
However, the farming of livestock has as its greatest output of GHGs not as a result of CO2, but methane (CH4) and nitrous oxide (N2O). CH4 in particular has greater green house gas effect than CO2, although its time lingering in the atmosphere is smaller.
So great are the emissions created by the consumption of meat, red meat in particular, that Weber and Matthews (2008) found that
only 21-24% reduction in red meat consumption, shifted to chicken, fish or an average vegetarian diet lacking dairy, would achieve the same reduction as total localization
Localisation refers to the concept that the closer to home we source our food, the lower the GHG emissions required. This study, based on observations in the United States, raises the point of how great an impact that a reduction in red meat and related product consumption can have on GHG emissions.
This is just an example of the questions science is asking itself to determine how much impact such changes can have on the environment.
Lastly, the population of the human race throughout the world is growing, and growing quicker than ever before. It is projected to reach a climax mid-century, but the growth until then is extreme. The reliance on the meat industry to feed the population will place a greater need on agricultural farming and, therefore, land clearing and GHG production, as more farms and livestock are required.
I don’t proclaim that Veganism is the only means to an environmental end, as Weber and Matthews above make clear. I don’t have any doubt that if the majority of the population that consume animal products limited their intake even to half the amount they currently consume, this would dramatically reduce GHG emissions.
For me, the logical extrapolation of this information was to stop eating all animal products to get the greatest environmental impact.
Further, there is no doubt that politics, culture and global capitalism will affect the extent that such a change in diet will have worldwide.
For example, I have heard the argument that all the grain used to feed animals could feed the third world, assisting in an elevation in living standards (and a reduction in the reliance on meat as cheap food) in the third world, reducing emissions in both the first and third worlds as a result. This could be plausible. But such an oversupply of grain will reduce demand and lower its price, and no grain supplier will allow that to occur. Warehousing the surplus, limiting supply and maintaining the price will be of greatest benefit to the grain industry.
Such societal factors have been cited by Richard Eckard and he concludes that a reduction in meat consumption is not a viable option for all of the world population, and that technological advances are the better way forward. However, Popp et al (2010) have managed to include such factors in their models predicting the likely effects of a reduction in meat consumption and arrived at the opposite conclusion.
I don’t mean to imply that this is how society should work or resign myself to the contention that it this is how it will always work; I implicitly argue that there are better social structures that humans could use to both our and the environment’s advantage. This is an argument for a more detailed paper, but is something that Naomi Klein recently wrote at length about, and with whom I completely agree that climate change is a symptom of the much larger problem of societal, particularly economic, structure.
The choice of diet is a unique and individual choice and not something that can compelled upon someone.
I hope that this article inspires even a few to consider more deeply their eating habits, and perhaps change a few diets.