Agriculture’s Impact on Greenhouse Gases
To comprehensively cover animal agriculture’s impact on greenhouse gases (GHGs) is to aim at a moving target. I will continue to expand on this topic in publications because I believe it is absolutely critical that this information reach the public.
Let me first review what we know so far:
Our animal food–based diets seem to have an enormous and almost entirely overlooked negative effect on the environment, including massive inputs of harmful greenhouse gases. Other negative effects on the environment include:
Loss of rainforest, savannah, and other important ecosystems to grazing or growing crops for livestock
Air and water pollution
Loss of biodiversity
Greenhouse gas emissions attributed to excretions of livestock management
Methane from enteric fermentation
CO2 from respiration
Methane from manure management
Nitrogen emissions from stored, applied, and deposited manure
And that is not a complete accounting.
The quantity of greenhouse gases emitted from animal agriculture is a question of considerable debate. The Food and Agriculture Organization of the United Nations (UN-FAO) attributes 18% of worldwide greenhouse gases to the production and consumption of livestock. This is a greater percentage of GHGs than those produced worldwide by all the cars, trucks, buses, trains, and planes combined. I have reason to believe that the figure of 18% will continue to rise as scientists become increasingly willing to include overlooked and undercounted sources of greenhouse gas emissions associated with animal agriculture.
Unfortunately, there is an unwillingness to reflect on our own actions and to question deeply held beliefs about food and entitlement. This was painfully illustrated in Al Gore’s rallying cry for the environment, An Inconvenient Truth, in which the only images of livestock were a nostalgic look at the past. As you will read in the Washington Post article by Ezra Klein, “The Meat of the Problem,” recommending that people not eat animal products “doesn’t poll well,” and major environmental groups have abandoned this recommendation.
How do we take this extremely unpopular idea and make it part of the mainstream consciousness? We must be willing to do what we are told again and again is impossible. But we have been told about impossible challenges before. And from what I know of the students in these courses, the seriousness of your study and willingness to make changes in your own lives, I see reason to hope. I see reason to hope from the people promoting plant-based nutrition in Alaska, in Sri Lanka, in Pakistan, and in the cattle country of Montana. These brave, calm, unrelenting voices of reason give me hope in the midst of the foolishness of modern times.
I applaud efforts to mitigate livestock’s threats to the environment, but I must stress the importance of reducing demand. These animals are here by our choice, encouraged by ill-conceived policy, and promoted by food companies that do not factor public health into their bottom lines.
I don’t want to vilify cows, which my family depended on for our livelihood, or other livestock. But we cannot assume that because they are not made of steel, because they do not come with a smokestack, they are just part of nature. We cannot ignore their excess population and the fact that, like cars, they are here at our pleasure and are emitting harmful greenhouse gases.
As you go forward, watch this topic and be ready for perhaps the most compelling argument of all for a switch to a plant-based diet. It is not just our personal health that is at stake, but the climate as well. These are incredible times and history is full of unlikely winners. Perhaps you and I and this planet will one day join their ranks. ~ T. Colin Campbell Foundation.