Newsweek's Green Rankings, 2014

Ball Corp. manufactures 50 billion cans annually. At its plant in Golden, Colorado, Ball leads a recycling program that has resulted in 560 metric tons of recyclables being dropped off every year. RJ Sangosti/Denver Post/Getty

The plane flew off, leaving three scientists alone on a vast ice shelf in Antarctica. As the twin-engine aircraft became a speck in the sky, they realized they were utterly alone; the nearest human settlement was 2,000 miles away.

"It was beautiful and scary at the same time," says David Holland, a New York University oceanographer, and one of the three. They would be there for 10 days, and their mission was to figure out how the way we live in New York; Omaha, Nebraska; Lagos, Nigeria; Beijing and São Paulo has affected the world's most remote places—and how those distant changes are coming back to haunt our cities.

"Climate change, once considered an issue for a distant future, has moved firmly into the present." With these strong words, the U.S. Global Change Research Program opens its 2014 National Climate Assessment, an 841-page call to arms against climate change denial. It's only the most recent of many official documents and publications to state the planet has a problem, but in some ways this was the most dramatic announcement yet of a political will to address the reality of an impending environmental disaster.

However, there's only so much the government can do; the private sector is perhaps the most important player in this global drama. That's why, in partnership with Corporate Knights Capital and leading sustainability minds from nongovernmental organizations and the academic and accounting communities, Newsweek has ranked the world's largest companies on corporate sustainability and environmental impact. We worked to make the rankings as relevant, meaningful and transparent as possible. They're based on our new and improved rules-based methodology that utilizes only publicly available data—no black boxes here.

Of course, no ranking system is perfect. Comparing a company that makes chemicals to one that provides financial services makes comparing apples and oranges seem relevant, and easy. Nevertheless, it is useful to isolate metrics that can cut across all industries (and, of course, it is perhaps most informative to judge any company relative to its peers). The reasons why become clear when you look toward the bottom of the rankings.

As we dug into the data on the 500 largest companies (by market capitalization) both globally and in the U.S., it became apparent that far too many companies—particularly those based in the U.S.—are not yet transparent enough when it comes to resource use and environmental impact. Nearly 300 U.S. companies did not report on their water use, for example, and around 200 didn't bother reporting their energy use. Our hope is that the penalties connected to these reporting gaps in our rankings methodology in some small way encourages these powerful corporations to make their environmental impact a higher priority.

SEE THE LISTS: Top 10 Green Companies in the World | Top 10 Green Companies in the U.S | Full World Rankings | Full U.S. Rankings

Our Green Rankings Section