New science reveals agriculture’s true climate impact | The Barley Mow |

"... a group of scientists at the University of California, Berkeley have found a way to “fingerprint” various sources of nitrous oxide — and they’ve determined that the accelerated increase in atmospheric nitrous oxide in the last few decades has indeed been due to synthetic nitrogen fertilizer use.


The researchers accomplished this feat through a fascinating technique — using a natural “archive” of air frozen in Antarctic ice combined with an actual archive of air samples taken from a (stunningly beautiful) pollution tracking station in Tasmania, Australia.


In their analysis, published in the journal Nature Geoscience, the scientists found that microbes in heavily fertilized farm fields produce nitrous oxide heavy with a particular isotope (nitrogen-14, for those keeping score at home). Their analysis also showed differences in the samples between the two sites that suggest the ability to create a geographical emissions map."