UPS Inc. has set a goal to reduce the carbon intensity of its transportation operations by 20 percent in the next six years, after meeting an earlier goal three years early, the company said.

The company had set a goal in 2013 of reducing overall carbon emissions by 10 percent by 2016. After meeting that goal early, UPS now plans to reduce emissions by 20 percent by 2020.

"As a global logistics company dependent on vehicles and fuel to move nearly 17 million packages and documents a day, sustainability and growth are inextricably linked," said Scott Davis, UPS chairman and chief executive officer. "Our ability to grow our global shipping volumes and reduce total carbon emissions should be a signal to business that it is possible to do more for the environment while also serving more customers and adding more value."

UPS moved 3.9 percent more cargo last year compared to 2012 and at the same time reduced its emissions by 1.5 percent. The company operated 3,647 vehicles powered by alternative fuels, the company said.

In March, UPS announced it would invest $70 million to add 1,000 propane autogas trucks and the fueling infrastructure to support them. UPS also reduced its fuel consumption by 1.5 million gallons through route optimization initiatives.

UPS included the new goal in its "Committed to More" initiative that follows from its 2013 Sustainability Report. View more at the UPS Sustainability website here.