Something to ruminate on

*Brian sent me this article on the carbon-capturing potential of cows.
There are parts of the article I agree with. I've colour-highlighted the passage I found most important. All comments welcome :-)

COWS CONSERVING CARBON

MATTHEW CAWOOD

WHEN it comes to climate change, livestock animals have become confused with human management of livestock, Tony Lovell says.

A cow is just a cow, the co-founder of Soil Carbon Australia observed, but how a cow impacts on the environment is entirely the product of human decisions.

Those decisions are particularly relevant when the cow is being targeted as a methane-producing agent of climate change, in Mr Lovell's view.

Instead of positioning cattle and sheep as problems, he suggested that the focus switch to how humans manage both livestock and fire.

A co-founder with Bruce Ward of Soil Carbon Australia, Mr Lovell recently contributed to Richard Branson's Carbon War Room initiative in London.

The non-profit organisation is dedicated to harnessing entrepreneurial drive in the development of climate change solutions. Managing livestock as a solution, rather than a problem, was one of the options on the table.

Mr Lovell has pursued lines of enquiry that put livestock in a more holistic light.

Grazing animals play a vital role in the ecology of grasslands, in that they provide an efficient way of cycling plants.

Left unchecked, a grassland will grow until it becomes moribund and dies off. The only means left to quickly cycle the plant material is fire - a tool used to excess across the world.

NASA estimates that fires each year consume 1.8-10 billion tonnes of biomass, releasing billions of tonnes of greenhouse gases.

Mr Lovell asked, what if each year the edible portion of the biomass that is now burned is instead eaten by livestock?

Scientists suggest cycling the biomass through livestock wouldn't create as much greenhouse gas as fire, despite livestock's reputation in this area.

Mr Lovell asked a CSIRO scientist to calculate how much greenhouse gas would be emitted by burning a tonne of grass, and feeding the same tonne of grass through a cow.

The response in rough terms (given that much depends on the feed quality) was the "greenhouse gas intensity" of burning the grass would be 3.6 times more than if it was eaten by cattle.

And if grass is eaten, instead of being burned, it produces food - potentially quite a lot of it.

Mr Lovell roughed out some calculations under which two billion tonnes of biomass was eaten by livestock instead of being burned, and arrived at a figure of around 100 million tonnes of extra meat production.

Global meat production in 2000 was about 56 million tonnes, according to the Food and Agriculture Organisation.

Those extra animals would produce extra methane - but the net greenhouse effect would depend on how they were managed.

"Properly managed" livestock - that is, livestock managed to allow plant recovery from grazing and build-up of biodiversity - have been shown to be a regenerative force on degraded rangelands across the world.

If livestock were managed in a way that improved soil and groundcover on currently degraded land, that would immediately increase "grass albedo" - the ability of the Earth's surface to reflect heat, rather than store heat as happens when sunlight hits bare ground.

More rough calculations - by an engineering professor at a Scottish university came up with the figure that if grass albedo was employed, only 0.4 per cent of the Earth's land area would be needed to repair the "thermal damage" done to the planet's surface since preindustrial times.

Mr Lovell also contacted two US professors who discovered that if methane-emitting landfills are covered in fertile, biologically active soil, most of the landfill's methane is oxidised by bacteria in the soil.

Put all the "back-of-the-envelope" figures together, Mr Lovell said, and they suggest that properly managed ruminant livestock have a place in addressing climate change.

"I'm not saying we have the answers, but if we think of livestock in terms of environmental cycles rather than just as methane producers, we get a very different picture," he said.