Saying “California clamps down on cow farts,” Fox News has its ends mixed up.
Instead, regulators are concerned with cow burps.
Cows burp a lot because of what they eat. Called the rumen, the front section of their four-part stomach is particularly adapted to processing tough to digest fiber-laden substances like grasses. One by-product of the process is hydrogen and carbon dioxide gas which combine, make methane, and soon are burped into the world. Together these burps compose almost one-quarter of U.S. methane emissions,
A potent greenhouse gas, methane creates 25 times more warming than CO2 during 100 years. Or the next time you eat a steak, just think of the cow. You would need more than 130 pounds of rice for the carbon dioxide equivalent (CO2e) of a six-ounce Kobe steak that was produced on a commercial farm.
As you would expect, growing a tomato or an apple also generates much less CO2e than steak:
The home of 5.2 million cows (including calves), California wants to reduce its methane emissions. With 2018 as the new law’s start date, their goal is to cut methane pollution to 40% below its 2013 levels. Already methane digesters have been turning manure into clean power at 15 dairy farms. In addition, researchers will look more closely at what cows eat, how they breed and where to capture the methane.
The World’s Methane
Below, xkcd shows that the earth’s methane problem is massive. However, according to recent research from Australia, it might not be as bad as we thought. In Australia, new testing indicates that their grassland cows emit far less methane than dairy cattle.
My pink arrows point to the ruminants:
Our Bottom Line: Externalities
My sources and more: Always a handy source for interesting news, Vox alerted me to the California legislation. Then for more detail, the Sacramento Bee was ideal as was this article on new research from Australia. Please note that the paragraph describing the impact of methane was in a previous econlife post.