They evaluated the remaining 350 companies using key environmental, social, and governance performance indicators, including waste productivity, CEO-to-average-worker pay ratio, leadership diversity, and employee turnover.

FORBES: The World's Most Sustainable Companies

Not surprisingly, the countries are wealthy and among the world's greenest as well, according to the Environmental Performance Index, a joint product of Columbia University and Yale University, which measures performance against 25 indicators, such as measures of air pollution, water supply or use of natural resources.

FORBES: The Most Energy-Efficient Countries