Interesting stuff indeed! For the claims have always been that by producing meat, we are responsible for a lot of CO2. Fact is that if sheep and cows never chewed the grass down, lightning strikes each summer would set off huge fires in much of our country. Those lambs don't just create great firebreaks, they are also very tasty :)

Professor Tim Flannery, the 2007 Australian of the Year, said in his recently published Quarterly Essay, Now or Never (issue 31 2008) “I believe that in a world facing a food shortage and a climate crisis, livestock represent a potent weapon in the fight to stabilise our climate. It is argued by those who oppose meat eating that cattle produce methane, and therefore a better strategy would be to destock the rangelands altogether. But is it really desirable to abandon use of the world’s rangelands at a time of perilous food security? Furthermore, if the rangelands were to be de-stocked and left unmanaged, it is likely that fire would burn the vegetation, which would lead to more carbon entering the atmosphere and huge increases in nitrous oxide.”

So the big question is, WHY IS THIS STUFF NOT PUBLISHED? The relevant information is obviously already at hand so the only questions are: 1. How much will it cost to engage a suitable boffin to write it up? 2. Where do we get the funds from? and, 3. When can we start describing incompetent National Parks fire management in terms of millions of lost cow feed equivalents. And while they are at it, they could do the same with termite methane.

Matt, good point, but it plays on a false (yet popular) image of carbon movement: as emissions or input-output systems, rather than seeing the big picture of the entire cycle. Whether by fire or cow, most of the carbon in the grass will go back to the atmosphere sooner or later. The fire is just quicker, and supports far less biodiversity on its way. The carbon in the burned grass does no more biological work, and is merely converted into waste heat plus CO2. The speed of oxidation is of paramount importance in how well we can turn atmospheric carbon into longlasting soil carbon. Through the cow is better because it's slower, and does more work along the way. Peter soilcarboncoalition.org

We can use this info for more than just raising the height of our personal soapbox. Grass has more optional uses awaiting it than just fire or cattle feed. The lessons from this study include: Crash graze (with sheep preferably, otherwise cattle) areas which would otherwise be deliberately burnt as a pasture management tool. For cattle, invisible electronic fences will soon allow cheap crash grazing options to help protect populated areas and vulnerable crop as well as avoid the need for fires in some northern grasslands. Be extra careful to avoid accidental fires, be vigilant against arsonists and stupid people. Enhance the quick response options such as the proposed Victorian jumbo jet fire tanker so that a lot of fires can be quelled quickly before they reach their damaging potential.

There are two key perspectives that have been widely missed in this debate: i) the carbon in the ruminant production systems is largely already available to the plants, animals and atmosphere and is simply recycling among these pools. This contrasts with the burning of carbon fuels, which are releasing carbon that is locked up in long term stores. ii) Ruminants produce less methane in digestion than allowing an equivalent amount of forage to decay or rot. It is unthinkable to have a planet without ruminants.

Interesting, Matt. But in some ways, a false dichotomy. In real life, it is seldom cows OR fires. We're more likely to have both, with the main greenhouse gases from cows being methane and nitrous oxide. There have been any number of studies published on the greenhouse emissions of ruminants, such as Flessa et al, in Agriculture Ecosystems and Environment (Sept 2002). And CSIRO did a lot of work on modifying the rumen, so as to produce less gas. And on fires, the Bushfire CRC has been researching emissions. See for example the Highfire Research project.