Voluntary greenhouse gas accounting has become common in the private sector, but is it helping?
Ten years ago, as part of a sustainability initiative, Walmart decided to take a look at its greenhouse gas emissions. The retail giant not only tallied up the carbon footprint of its trucking fleet and supersize stores, it also set out to quantify the greenhouse gas emissions associated with the countless products offered on its shelves. With the help of the Environmental Defense Fund, the company calculated that these goods accounted for the vast majority of its emissions — between 90 and 95 percent, says Jenny Ahlen, a supply chain expert at EDF who works with Walmart.
Armed with information about the sources and sizes of its supply-chain emissions, the company vowed to reduce them by the equivalent of 20 million metric tons (22 million tons) of carbon dioxide by 2015. Walmart recently announced that it met and surpassed that goal by implementing a number of measures, from increasing the energy efficiency of household products like lightbulbs to reducing the amount of food wasted in processing, in transportation and at stores, Ahlen says.
While critics say Walmart still has a long way to go to minimize its climate impacts, its success in reducing its supply chain emissions illustrates the idea that “to measure is to manage,” says Dexter Galvin of CDP, a non-profit organization that collects corporate climate information. That mantra embodies the rationale behind greenhouse gas accounting, which has become increasingly common in the private sector, especially in the U.S. and Europe.