Laser “Gas Detective” Probes Methane Emissions from Cows

March 7th, 2011 by Tina Casey

It’s common knowledge that one of the single largest sources of greenhouse gas pollution related to human activity is methane emissions from livestock (yes, cow farts). However, when it gets down to specifics, the figures are somewhat elusive, partly because most estimates have been made based on measurements from individual cows. Now an international team of scientists has come up with a way to deploy lasers to measure methane emissions from entire herds.

Methane Emissions from Cows

The U.S. EPA goes with the figure of 80 million metric tons of methane annually. That includes the global methane emissions from all ruminant livestock, meaning cows, goats, sheep and any other animal that chews its cud (blech, but whatever). Even just counting large ruminants, the numbers add up; in the U.S. alone there are an estimated 100 million cattle all contributing their two cents to climate change.

A Solution to Livestock Methane Pollution

According to EPA, grazing and dietary engineering can help reduce methane emissions, and so researchers have been tinkering with methane-reducing feed variations such as algae, fish oil, and even curry. Having an efficient, cost-effective means of measuring progress (or lack thereof) is the key to success, and that’s where the laser equipment comes in. It enables scientists to take discrete measurements under real-life conditions in normal livestock operations, which presumably mitigates stress and other variables that might be present when individual animals are sequestered for measurement.

Lasers for Measuring Methane

The scientists, from Canada and Australia, have tested their technique on a small herd of 18 cattle. The members of the herd were provided with global positioning devices to monitor their movements along with wind speed and directions, and “open-path” lasers were used to measure methane concentrations directly above the herd every ten minutes. Open-path technology is commonly used in gas detection, specifically by the petroleum and chemical industries to to detect gas leaks, so the application to cows makes perfect sense.

Image: Cow by seanmcgrath on flickr.com.

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Tags: cattle, greenhouse gas, Methane, open path laser, U.S. EPA

About the Author

Tina Casey Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. Views expressed are her own. Follow her on Twitter @TinaMCasey and Google+.

http://www.fishoilblog.com/ Marshall @ Fish Oil Blog

I found this post searching for fish oil. Interesting that fish oil can be methane reducing. I’ve never heard that and I operate a blog about fish oil.

I’ve heard that cow methane produces a greater greenhouse gas effect than all the cars in the world! That’s a great point from Martin about termites. Maybe greenhouse gases aren’t the culprit after all… I’m starting to believe we’re heading for a long period of global cooling, not warming. Is that blasphemy?
- Tina Casey
  
  Marshall, blasphemy has application to religion. It’s not the most objective way to frame the position of those you disagree with in a science field, and it does a disservice to your own position.
martin weiss

Very interesting but I think the amount of greenhouse gas emitted by termites far exceeds the amount cows emit. We have no way, I know of to estimate the amount annually or how to control it. One way that is clear is to eliminate clear cutting forests, especially in the tropics, where termite “blooms” occur with the availability of wood on the ground.
- Tina Casey
  
  Thank you, Martin. As far as human contributions to the termite population go, controlling the availability of wood in buildings and other structures is also a factor.