Reply #79: I don't think they have made a leap [View All]

> Does anyone know if there really are more ruminants on the planet
> today than there were before Buffalo Bill nearly exterminated the Bison
> and others wreaked a lesser carnage in Africa?
This is a subject that has been looked at before, by environmental scientists. Try the FAO's Livestock’s Long Shadow –Environmental Issues and Options - which is referenced in the Lancet article.

There was a letter to the editor in Scientific American (June 2007, don’t have a link to it) asking a similar question:

“In ‘Methane, Plants and Climate Change,’ by Frank Keppler and Thomas Roeckmann, two graphs compare sources of methane in the atmosphere during preindustrial times with those of today. Ruminants are listed as a major source of current emissions but are not included in the preindustrial chard. Did as many as 70 million bison really produce that much less methane than today’s cattle?”

“Keppler replies: Although wildlife certainly produced methane in preindustrial time, this output was just a minor fraction of the 233 million metric tons of yearly global methane emissions. According to estimates made by environmental scientist Susan Subak and her colleagues in a 1994 article for Chemosphere, the total production of methane by wild ruminants in that period was no more than 10 million metric tons a year - a figure that takes into account the North American bison population (which Subak estimates to have comprised 60 million animals) and the natural ruminants of Africa and other continents. An estimated 1.4 billion head of cattle populate the world today - far more ruminants than existed in preindustrial times. Furthermore, modern cattle are bred for productivity, which probably leads them to emit more methane than their wild relatives did. Estimates put their methane production at 115 million metric tons a year.”

http://www.badastronomy.com/bablog/2007/07/11/solar-cooling/#comment-122415