Today, I will continue with animal farming and how the release of methane and other GHGs like Nitrous oxide can cause global warming.
What is Methane and why is it important?
Methane (CH4) can emitted by natural sources such as wetlands, as well as human activities such as leakage from natural gas systems and through animal farms. Natural processes in soil and chemical reactions in the atmosphere help remove CH4 from the atmosphere. Methane’s lifetime in the atmosphere (12 years) is much shorter than carbon dioxide (CO2), but it is more efficient at trapping radiation than CO2. In other words, as CH4 is released into the atmosphere, its efficiency at absorbing radiation contributes to the warming of the Earth. As sunlight (both radiation and insolation) reaches Earth’s surface, it can either be reflected back into space or trapped by the Earth. GHGs like CO2, and CH4 absorb energy, slowing or preventing the loss of heat to space. This process is commonly known as the “greenhouse effect”.Pound for pound, the comparative impact of CH4 on climate change is over 20 times greater than CO2 in a time scale of a 100-year (Epa.gov, 2014).
For an interactive experience as to how Greenhouse effect and warming is caused by GHGs, please try this: http://epa.gov/climatechange/science/causes.html#
Management of Methane emission from animal agriculture
Since animal agriculture is the no.1 contributor to anthropogenic emission of methane, what can we do about it?
One of the proposed manner is the recycling of the manure (which produces 85% of the methane), creating a close-looped economy, where waste is reused. Watch the following Youtube Video.
In summary, the video explains how a cow farm has managed to convert the cow manure into electricity power through the biogas disgester technology. Keeping the manure heated at 110 degrees Celsius for 21 days, the manure releases methane gas, which is then used to generate the electricity. The farm is fully powered by the electricity generated from the farm’s manure, and extra electricity generated is sold to the local power utility station to power residential buildings.
As the biogas digester ensures that animal farming can be unpollutive, is there a need for a dietary revolution?
I will answer this question in my next post.
Stay Tuned 😀
Epa.gov, (2014). Methane Emissions | Climate Change | US EPA. [online] Available at: http://epa.gov/climatechange/ghgemissions/gases/ch4.html [Accessed 22 Mar. 2015].