Recently, I read an article in which Bill Gates claimed that the beef production in the agricultural sector is causing global warming. He indicated that the cows generate a lot of methane gas, which is the reason for global warming, thus climate change. He also suggested that countries should use plant-based meat if they want to stop climate change.
Bill Gates may be right that the agriculture and food production systems are causing climate change. However, he may not realize that the cows have very little to do with causing global warming, as the methane gas produced by the cows is very minimal as compared to the other sources of greenhouse gases.
Carbon dioxide, as well as methane gas, are among the major greenhouse gases causing global warming. The major source of these gases is the agricultural sector, where the land is being used extensively for crop production.
In addition to carbon dioxide being emitted from burning fossil fuels, there are also silent sources of carbon dioxde and other greenhouse gases coming off the soil that are less talked about, but have a major impact affecting global warming.
Carbon dioxide is only one among many other gases such as methane gas, nitrous oxides and others that are being emitted from the soil into the atmosphere continuously. Soil is a very dynamic component of the environment, with millions of microbes living in a unit of soil at any time. The microbes produce large amounts of carbon dioxide under drier conditions, or aerobic, which can potentially be emitted into the atmosphere each time we disturb the soil by tilling, plowing and/or any other disturbances such as off-roading.
At the same time, under the saturated conditions followed by a major rain event, millions of anaerobic microbes take over and generate tons of methane gas that can potentially be emitted into the atmosphere instantly. Additionally, it is worth mentioning that the rice paddies all over Asia, where rice is the staple food, are another major surce of methane gas emission into the atmosphere. Every time a rice farmer in China or in the Philippines floods their field before planting the rice seedlings, they flood the soil, thus providing an anaerobic condition in which it emits huge amounts of methane gas into the atmosphere.
Both carbon dioxide and methane gas coming off the soil can be controlled and reduced to a minimum with just simple techniques. Carbon dioxide can be captured by plants through the photosynthesis processes. Yes, we can capture a good bulk of the carbon dioxide that is being released from the soil source by planting trees and other vegetative plants.
In this respect, the plants are called the sink – where the emitted carbon dioxide gets captured by the leaves of plants through photosynthesis and then converted into protein.
There are a few other factors that affect the atmospheric greenhouse gases that we can control. We now have the knowledge and the know-how to control the carbon dioxide emission frm the soil, which is the major source where the bulk of the carbon dioxide originates from. We can actually store a large portion of carbon in the soil through a process called carbon sequestration, thus reducing its emission into the atmosphere as CO2.
In our soil lab at the University of Guam, we are experimenting with the use of “biochar” as a practical technique for sequestering carbon in our research plots and monitoring the carbon dioxide emission following the application of biochar.
As for the methane gas, which is mostly coming from the rice paddies for the most part and not the cows, there are other alternatives to rice production as well. I attended a conference a few years ago, where a researcher showed converting the wet rice production into dry rice production can be less labor-intensive and more efficient while producing better crops. In my conversations with a prominent soil scientist during a conference, I learned that the best rice in the world, the “Basmati” rice, he long grain, is produced via dry land farming.
In short, to reduce the effect of greenhouse gases from the agricultural sector, we don’t have to punish the cows for burping too much methane gas. Rather, we could reduce the sources of methane gas as well as the carbon dioxide emission from the soil underfoot.
My conclusion is that, if we are going to reduce the negative impact of carbon dioxide as well as the methane gas on climate change, not only do we need to reduce the man-made carbon dioxide sources of cars, factories, etc., but we also need to seriously think about and act on protecting the soil underfoot which is the major source of CO2 and the methane gases. Furthermore, we need to plant more trees and preserve them, so they can act as major sinks and prevent a large amount of carbon dioxide from reaching the atmosphere by capturing it via photosynthesis.
Mohammad H Golabi, Ph.D., is a professor of soil and environmental sciences at the University of Guam College of Natura and Applied Sciences.