Between the depressing crisis in the capital markets and the presidential campaign, which at least has the virtue of being entertaining, there’s almost no air left in the media climate for other stories to breathe, as Stephen Colbert, pointed out, amusingly, the other night on The Colbert Report. (When a special prosecutor was appointed to investigate the firing of U.S. attorneys, The New York Times buried the story with a single column headline on page 16.) And yet life goes on, really. Here are some stories from the world of business and sustainability that you may have missed:

Wal-Mart to dump (fewer) plastic bags: At the Clinton Global Initiative, Wal-Mart promised to reduce its global plastic shopping bag waste by an average of 33 percent per store by 2013. Other stores have been more aggressive in cutting back on plastic bags—Ikea is getting rid of them sooner—and some cities, led by San Francisco, are moving to ban them entirely. But because of its scale, Wal-Mart matters.

Matt Kistler, who leads the sustainability efforts at Wal-Mart, said in a news release: “If we can encourage consumers to change their behavior, just one bag at a time, we believe real progress can be made toward our goal of creating zero waste.” He said the company plans to eliminate 9 billion – billion! – plastic bags from existing stores. Among other things, Wal-Mart will offer reusable bags for 50 cents, train its staff to use fewer bags and decrease the amount of plastic going into each bag. (It will not, however, charge customers for plastic bags, at least not now.) The company said it will cut plastic bag waste by 50% outside of the U.S. and 33% in the U.S.—a sign, not that we needed it, that Americans can be counted on to be more wasteful than our neighbors.

The Environmental Defense Fund, which has a couple of full-time staffers working at WMT’s Bentonville, Arkansas, headquarters, helped the giant retailer develop its plan. Gwen Ruta, who oversees corporate partnerships at the business-friendly NGO, said, “Plastic bags clog our landfills, litter our roadways, harm sea turtles and other wildlife, and gobble energy in production.” She called on other retailers to curb plastic bag use.

Wal-Mart calculated that its efforts could reduce energy consumption by about 678,000 barrels of oil per year and reduce CO2 emissions by 290,000 metric tons per year – equivalent to taking more than 53,000 passenger vehicles off the road. The company is pushing ahead on other fronts to reduce packaging, notably by getting its suppliers to use less.

Enterprise promotes car sharing: The St. Louis-based rental car giant says it is expanding its business-to-business car sharing service, called WeCar, across America, after testing it in its home town. This pushes Enterprise closer into the space now dominated by Zipcar, with U-Haul and Hertz ready to follow, as USA Today reported.

For now, Enterprise’s WeCar will be available to corporate customers, governments and universities. The idea is to offer students or people who take public transit or car pool to the office a way to do errands easily and inexpensively during the day. The WeCar fleet is aimed at the environmentally conscious consumer; it’s primarily made up of hybrids and other fuel efficient cars. You can watch a video about WeCar here. Enterprise is currently offering the program at Washington University in St. Louis, Recreational Equipment, Inc. (REI) in Kent, Wash., and Google in Mountain View, Calif.

Enterprise is an impressive company. I wrote a column back in January about its efforts to “green” its fleet, promote renewable fuels and support environmental causes. Like Wal-Mart, Enterprise, which also owns the Alamo and National brands, is big enough to make a difference—it owns about 1.2 million cars.

Chipotle makes its own power: You know you can get tacos and burritos at Chipotle Mexican Grill but if you happen to live near Gurnee, Illinois, a small town midway between Chicago and Milwaukee, you can get a wind-powered meal, too. A six-kilowatt wind turbine on the site will generate about 10 percent of the store’s electricity, the company said this week. The stand-alone outlet also recycles its rainwater, uses super-efficient toilets and faucets, saves energy with LED lighting. The company says it will seek LEED certification from the U.S. Green Building Council.

Chipotle also has been working with suppliers to offer fresh, local food, as I wrote in a column a couple of years ago. The company even buys pork from perhaps the most famous organic farmer in America, Joel Salatin of Polyface Farm (who Michael Pollan profiled in The Omnivore’s Dilemma), as the Washington Post reported here.

What strikes me about Wal-Mart, Enterprise and Chipotle taking steps to become more sustainable is that they will never be mistaken for New England-based crunchy granola-type companies, like Ben & Jerry’s, Tom’s of Maine or Stonyfield Farms. They are mass-market companies, run out of the middle of the country, that reach people of all ages, races and classes. What they do has ripple effects. By their actions, they are saying that caring about the environment is important and that it’s good for business–even if they are likely to be overlooked in these otherwise extraordinary times.