United Parcel Service Inc on Wednesday announced plans to buy more than 6,000 natural gas-powered trucks over three years and step up purchases of renewable natural gas (RNG) as part of a new $450 million investment to reduce the environmental impact of its 123,000-vehicle fleet. The latest move from the world’s largest package delivery firm comes as utility companies, investors and others seek to expand the use of RNG – which is derived from biogas by decomposing organic matter such as cow manure on dairy farms, discarded food in landfills and human waste in water treatment plants – to reduce greenhouse gas emissions. More >>