Former vice president Al Gore has joined a notable venture-capital firm that’s aiming to step up investment in green businesses. In his role as a partner at California-based firm Kleiner Perkins Caufield & Byers, Gore will investigate the potential growth of alternative-energy start-up companies and counsel the firm on related greenish investments. No stranger to capitalism, Gore has been a big advocate of “free trade” and was VP when NAFTA kicked in (um, thanks?). In 2004, he co-founded green investment firm Generation Investment Management with David Blood. GIM now handles $1.5 billion in investments, and under the deal with Kleiner Perkins, GIM will share its London offices with Kleiner, and Gore’s friend John Doerr will sit on GIM’s board of directors. But Gore insists it ain’t just about the money — at least, not just his money. Gore said he’ll donate his entire salary from his new part-time gig to the nonprofit Alliance for Climate Protection.