Sprint Nextel will call on its manufacturing suppliers to measure, report and reduce their greenhouse gas emissions, before asking them to have their own suppliers do the same.

A newly published analysis revealed that Sprint Nextel's manufacturing suppliers represent the largest source of supply chain emissions for the wireless communications giant. Manufacturers produce 83 percent of Sprint Nextel's total supply chain carbon footprint, while its top 10 suppliers account for 78 percent of total supply chain emissions.

"What was most surprising to see is just how much of our carbon emissions are wrapped up with just a few of our suppliers," said Darren Beck, Sprint Nextel's corporate responsibility manager.

Consulting firm Trucost performed the supply chain assessment in about four weeks, setting the stage for the next phase of Sprint Nextel's climate change supplier strategy.

"At this point, we're now preparing for how we will begin engaging our suppliers. As part of that process, the manufacturing suppliers will certainly be the first group we will be engaging," Beck said. "But that model by itself will be a bit of a challenge because of the other insight we gleaned from Trucost."

Although 83 percent of Sprint's supply chain emissions can be traced to manufacturers, only 7 percent is directly attributable to those suppliers.

"What that means is 93 percent of those emissions in our supply are really wrapped up with suppliers' suppliers, and with their suppliers," Beck said.

As a result, Sprint Nextel will begin a conversation with its manufacturing suppliers and ask that they do three things: track and publicly report their emissions if they haven't already done so; set a public emissions reduction goal; turn to their own suppliers and begin the same kind of dialogue.

"We're going to ask them to have that same conversation around tracking, reporting and reduction goals with their suppliers, and on up the chain," Beck said. "Once you get one or two connections removed, that is still something that we're still trying to figure out, as would anyone else who's taken any in-depth look in this space, is how do you drive that change further upstream. We'll be working on that one for a while."

Sprint Nextel has committed to reducing its own absolute emissions by 15 percent by 2017. The company also wants 90 percent of its suppliers to meet its social and environmental criteria by the same year.

Laying the foundation for the initiative are Sprint Nextel's efforts to make its devices greener by removing environmentally sensitive materials and improving energy efficiency, Beck said. Over the last two years, the company has communicated to its manufacturers its vision for more environmentally friendly products, along with design requirements and a scorecard to measure progress.

It remains to be seen if Sprint Nextel will also begin the dialogue with other types of suppliers, such as those in its next two carbon-intensive sectors: Professional, Scientific & Technical Services and Information Services. These sectors, combined with manufacturing, represent 95 percent of Sprint Nextel's supply chain carbon footprint.