Reuters: Simple changes in grazing practices could soak up millions of tonnes 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 …