Classes are filling up as fast as colleges can add new major and minors in green programs, as students demand the courses and employers wanted trained students, reports USA Today.

More than 100 majors, minors or certificates were added this year in energy and sustainability-focused programs at colleges nationwide, according to the Association for the Advancement of Sustainability in Higher Education (AASHE), reports USA Today. This is up from three programs added in 2005. Click here for AASHE’s list of academic programs in sustainability.

As an example, the Global Institute of Sustainability at Arizona State University started an undergraduate program in sustainability More >