Business Green: The Volvo Group has taken a step toward more fuel efficient trucks with a new partnership with the World Wildlife Fund (WWF). The company, whose brands include Mack Trucks, Volvo Trucks, Renault Trucks and UD Trucks, has become the world’s first vehicle manufacturer to join the WWF Climate Leaders program. The public-private partnership consists of roughly two dozen of the world’s largest companies that have committed to reducing their sizable carbon footprints, including Diversey, Johnson…