Methane has had a bad reputation on many fronts – including the delicate matter of dining room etiquette. But when it comes to greenhouse gases, methane is right up there with CO2, as a worrying contributor to global warming. And one of the biggest sources of methane comes from livestock. What's been missing is an easy way to keep tabs on how much methane is coming from cattle, and other domesticated grazers.
Now, in research to be published in the Jan/Feb2011 issue of Journal of Environmental Quality scientists have found out how to home in on the source of methane emissions within a herd – and there is literally no 'escape' that fails to escape the notice of the new technology.
Methane is a concern for climate scientists because it is a much-more potent greenhouse gas than even carbon dioxide – 25 times so, over 100 years. Fortunately, it is not being emitted in such large quantities as CO2, and is also scrubbed out the atmosphere naturally much more quickly. Even so, it is estimated to contribute up to a fifth towards mankind-stamped global warming. Cattle are thought to make up between 12% and 17% of that. So working out how best to reduce such emissions is acutely important.
To do so, scientists first need to properly measure the scale of the problem. If they have can measure cattle methane accurately, direct from the source, they will they have a better handle on the risks of those releases caused by human activity. But equally they'll have tools to measure the effectiveness of different livestock practices, in helping to cut those emissions.
Using a combination of open-path lasers, GPS sensors on the cattle – and accurate measurements of wind speed and direction – this new study shows that precise real-time methane tracking is possible. Methane releases can now be narrowed to a single point of release in a paddock, 77% of the time. Previous methods of directly measuring cattle have been hindered because they interrupt daily management practices.
Sean McGinn, the study's author, goes as far to say that this is a "significant advancement in assessing greenhouse gas emissions from the cattle industry." The new technique is even accurate enough to pinpoint the location of the source down to individual cattle. So that means cows really have no place to hide, when it comes to a noxious emission.