The largest environmental grassroots organization in the United States, The Sierra Club has named University of California- Davis as the Greenest College of the nation for the year 2012.

As per the Sierra Magazine's sixth annual ranking of America's greenest schools, 20,000 students hopped on bicycles and rode to the UC-Davis campus in 2011. More than 2,000 eligible colleges and universities in the United States were considered for the ranking, reports Huffington Post.

The Sierra Club significantly revised and expanded its survey this year for consistency with a detailed, standardized format developed by the Association for the Advancement of Sustainability in Higher Education.

Bob Sipchen, SIERRA magazine's editor-in-chief wrote in the press release, "With their ever growing emphasis on environmental responsibility, these schools are channeling the enthusiasm of their students, who consistently cite climate disruption and other environmental issues as the most serious challenges their generation must confront, while demonstrating leadership for other civic institutions."

UC-Davis was immediately followed by Georgia Institute of Technology. Stanford University and University of Washington came in third and fourth place respectively.

The ranking also dubbed as 'Top Cool Schools' considers a range of factors the school's commitment to sustainability, environmental initiatives and excellence in sustainability-focused academics. Additional factors also include energy supply, efficiency, food, academics, purchasing, transportation, waste management, administration, and financial investments.

The top 10 "Cool Schools" for 2012 are:

1. University of California, Davis

2. Georgia Institute of Technology

3. Stanford University

4. University of Washington

5. University of Connecticut

6. University of New Hampshire

7. Duke University

8. Yale University

9. University of California, Irvine

10. Appalachian State University