Which Is Worse: 1000 Cars or 1000 Cows?
Which is worse for the environment: 1000 gasoline powered cars or 1000 cows? No brainer right? The obvious answer would be the cars with all their carbon emissions and pollution. But the answer may be more complicated.
Recently, we received a comment on one of our posts saying that while it is great to reduce, reuse and recycle, the real cause of our environmental emergency is actually a gas that we don’t hear that much about…methane. We hear a great deal about carbon dioxide and our “carbon footprint”, but methane is a greenhouse gas that doesn’t get a lot of attention. We thought we’d do a bit of investigating and see what we could find on this gas and whether or not our efforts to to help slow down global warming would be better served concentrating as much or more on methane as carbon dioxide.
Let’s start with a very basic explanation of what greenhouse gases really do. Most of you have probably had some experience with an actual greenhouse. You probably know that, even on a cold day, if it is sunny outside, the temperature inside a greenhouse will be downright balmy. The greenhouse traps all the warm air and moisture inside and prevents it from escaping to cooler environment on the outside. The earth’s atmosphere acts in the same manner as a greenhouse and traps solar radiation allowing the planet to stay warm relative to the icy cold of outer space. An increase in the production and emission of greenhouse gases causes the atmosphere to trap more solar radiation and causes the earth’s climate to slowly increase in temperature.
Carbon dioxide or CO2 is probably the most well known greenhouse gas. But how does methane (CH4) stack up to it and which gas is actually the one causing more damage?
Did you know that methane is actually 20 times more effective at trapping heat in the atmosphere than CO2 over a 100-year period? Furthermore, according to the EPA, it is estimated that 50% of methane emissions are caused by human-related activities. In the United States, the largest methane emissions producers are landfills, livestock, natural gas and oil systems, and coal mining. For 2008, the EPA estimates that the digestive process and manure management of domestic livestock such as cattle, sheep and bison made up nearly 37% of the methane emissions for these top producers.
According to the website Cattle-Today, there are approximately 1.3 billion heads of cattle in the world. While Worldmapper and Worldometers estimate there were about 806 millions cars and light trucks in the world as of 2007. If we follow the calculation formulas done by Fat Knowledge a few years ago but with updated numbers, we get the following:
A gallon of gasoline turns into 20 pounds of CO2
- Average car drives 15,000 miles a year and gets 30 mpg (bear in mind these are my estimates and the mpg is probably high)
- 15,000 miles /30mpg = 500 gallons of gasoline a year * 20 pounds = 10,000 lbs of CO2 a year
A cow produces up to 110kg of methane a year
- Methane is over 20 times more effective in trapping heat in the atmosphere than carbon dioxide (source)
- 110 kg * 2.2 lb/kg = 242 lbs of methane * 20 = 4,840 lbs of CO2 equivalent greenhouse gases
A car emits a little over 2 times as much greenhouse gases as a cow. So what does this mean on a global scale? With the increase in the number of cars and light trucks over the past few years, especially in developing nations such as India, the 1.3 billion cows produce about 80% as much greenhouse gases as cars. However, that is not the whole picture…
A senior UN official and co-author of a UN report detailing this problem, Henning Steinfeld, said “Livestock are one of the most significant contributors to today’s most serious environmental problems”. Livestock production occupies 70% of all land used for agriculture, or 30% of the land surface of the planet. It is one of the largest sources of greenhouse gases, responsible for 18% of the world’s greenhouse gas emissions as measured in CO2 equivalents. By comparison, all transportation emits 13.5% of the CO2. It produces 65% of human-related nitrous oxide (which has 296 times the global warming potential of CO2,) and 37% of all human-induced methane. It also generates 64% of the ammonia, which contributes to acid rain and acidification of ecosystems. Livestock expansion is cited as a key factor driving deforestation, in the Amazon basin 70% of previously forested area is now occupied by pastures and the remainder used for feedcrops. Through deforestation and land degradation, livestock is also driving reductions in biodiversity.
So, what is the conclusion? While cars may emit more greenhouse gases than cows do on a individual basis, livestock actually appear to be more detrimental to the environment as a whole.
- Reduce our beef consumption. Become a vegetarian if you’d so desire. Goodness knows that is healthier for the planet and our bodies. But if that doesn’t appeal to you, at least limit your consumption of beef (and other meats for that matter). Eat more fruits, veggies and fish!
- Demand that cattle farmers improve the diets of their animals so they don’t burp as much. We must realize that this would initially increase the price of beef to the consumers but saving the planet isn’t free!
- Push for investment into biogas development which would allow us to capture and use some of the methane produced by livestock.
- Write our legislators asking for land use and soil conservation regulations. I know the idea of “government intrusion” is one that makes some people go very red, however there are some areas that simply require a larger response than that which an individual can do on their own. And, like it or not, the free market is driven by the mighty dollar, not by making choices which may decrease the profit margin but benefit that pesky “environment”!
Alright, I guess I’ll get off my soapbox now. What’s for dinner anyway? Me? I’m having fish (don’t worry, I’ve made sure it’s a sustainable variety!)…