Greenopia reports in their press release:
The greenest major retailer, receiving 4 out of 4 Greenopia Leafs was Ikea. Retail giants Walmart, Best Buy, and Office Depot were the next greenest, all receiving 2 out of 4 possible leafs.image via kitcowan/flickr
Greenopia used a comprehensive set of criteria to determine the ratings. Data was collected from the companies themselves pertaining to the transparency, renewable energy sourcing, transportation fleet, stock, consumer take-back programs, and green building initiatives.