Back in 2007, George Mason University's President Merten signed a pledge to become climate neutral by 2050. That means the university is actively taking steps to reduce its environmental impact, primarily the carbon dioxide (CO2) emissions associated with the university's operations, and then eventually offsetting the rest. Moreover, Mason agreed to incorporate sustainability into its academic and extracurricular offerings. Since that pledge, Mason has made real progress with those goals, completing several Greenhouse Gas Emissions Inventories to measure its emissions, producing its first Climate Action Plan which serves as a road map for achieving climate neutrality, and reporting on its sustainability progress with the Sustainability Tracking, Assessment, and Rating System (STARS) report. In 2014, Mason scored a Gold rating on that report. Additionally, from 2011 to 2015, Mason purchased wind powered Renewable Energy Certificates (RECs) to offset a portion of its electricity use. Buying RECs supports the development of the renewable energy industry in the United States.