The word “green” means different things to different people. For many developers and building owners, it’s what fills their pockets. But if you’re an environmentalist, it means something else entirely. However, sustainability is now officially poised to affect everyone in real estate. Last September Mayor Bill de Blasio committed New York City to reducing its greenhouse gas emissions by 80 percent below 2005 levels by 2050. That means it’s time for the industry to reconsider their favorite color.