By some estimates, buildings account for about 40 percent of greenhouse gas emissions globally. The biggest landlord in the U.S. is the federal government, and it’s making a new push for greener buildings, including here in Colorado. Robin Carnahan leads the General Services Administration, which oversees the buildings. She told Colorado Matters going green is a triple win, because it creates local jobs, reduces energy costs to save taxpayers money, and makes the planet a healthier place to live.