From Microsoft going carbon negative to Starbucks announcing a (somewhat vague) goal to become “resource positive,” it seems that major companies are announcing new sustainability efforts every day. But which ones are doing the most for our environment? An annual ranking from Canadian research firm Corporate Knights, revealed January 21 at the World Economic Forum meeting in Davos, Switzerland, scrutinized more than 7,000 companies to identify the 100 most sustainable corporations in the world.