General Motors is joining the voluntary U.S. Environmental Protection Agency SmartWay Partnership, which will drive benchmarking of fuel consumption and reduction of emissions by its freight shippers and carriers with the goal of further shrinking the company's carbon footprint.

If you're responsible for supply chain management or providing supply chain services, reducing your carbon footprint is likely becoming a priority. So how do you get there from here? One route to sustainability is ISO 14001 certification. Here's the Who, What, When, Where, Why and How of getting there.

Beginning in July 2013, Procter & Gamble will work with eight transportation carriers to convert up to 20 percent of its North America truck load shipments to natural gas vehicles within two years. By meeting this goal, it is expected P&G will incur savings for the converted lanes and reduce greenhouse gas emissions (GHG) by nearly 5,000 metric tons (or the equivalent GHG emissions from 1,000 passenger vehicles for a year).

An industry united on environmental issues will have greater impact than individual companies defining their own goals, says Daniel Côté, environmental advisor for Canadian shipping company Transport Desgagnés. It's not just big talk for Côté.

IBM has been recognized for the second consecutive year as the greenest company in the U.S., according to the Newsweek 2012 Green Rankings survey. A panel of independent judges ranked major companies based on numerous criteria, including their environmental impact, environmental management and sustainability disclosure. The survey is regarded as one of the most comprehensive analyses of environmental leadership, and IBM was one of 500 large U.S. organizations evaluated.