SINGAPORE (Reuters) - Simple changes in grazing practices could soak up millions of tons of carbon a year, helping fight climate change, improving farm productivity and earning farmers carbon credits, a scientist said on Tuesday.
But such measures needed to spread globally to more than 120 million farmers working grazing lands, such as savannah and shrubland, Andreas Wilkes of the World Agroforestry Center in Beijing, said.
The measures also needed to be backed by the United Nations in a broader climate pact to help farmers earn carbon credits as an incentive and to pay for changes in grazing management.
Rangelands hold up to 30 percent of the world's soil carbon and span more than five billion hectares, or about 40 percent of its landmass, Wilkes and a colleague, Timm Tennigkeit, wrote in a recent report.
In grasslands, most of the carbon is in the soil, except for treed grassland, which hold a sizeable portion above ground.
Wilkes said changing grazing practices, such as replanting one or more different plant species, or sealing off portions of grassland, can boost soil carbon content.
"It depends on what the problems causing or preventing proper management are," he told Reuters in a telephone interview.
"In some places, it will be there are too many animals, so you simply reduce their number. If the soil has already begun to degrade, then maybe planting grasses is the best option.
"It's a matter of education and often also supporting conditions, such as policies. None of it is rocket science."
Improved management of grazing lands has the potential to lock away between 1.3 billion and 2 billion tons of carbon dioxide-equivalent worldwide up to 2030, the report says.
"Most carbon-sequestering practices also have other benefits. Increasing soil carbon content will generally improve soil fertility," it says, leading to increased livestock productivity.
At present, only U.S. farmers can earn carbon credits through improved grazing land practices.
The Chicago Climate Exchange has created an accounting standard for emissions reductions from rangelands, such as plots farmed with modern equipment that precisely positions seeds and fertilizer instead of energy-wasteful tilling, or to restore previously degraded rangeland through rotational grazing.
But the CCX's standards have been criticized as being lax and doing little to slow climate change, since farmers have carried out such practices regardless of carbon credit incentives.
Wilkes said it was crucial the next phase of the Kyoto Protocol, expected to be agreed by the end of this year, included agriculture and sustainable land management.
He said the center was designing a pilot project together with the Food and Agriculture Organization in China.
The aim was to submit the project, together with methods to measure and verify rangeland soil carbon sequestration to the Voluntary Carbon Standard.
The International Emissions Trading Association and the World Economic Forum are among the groups backing the VCS, which aims to provide global benchmarks to ensure a credible voluntary carbon market.
"Once the politicians can see the market is putting its money in rangelands and there are viable methodologies that everyone thinks are sound, then that may open up the opportunities at the international level," said Wilkes.
Editing by Clarence Fernandez