Some environmentally friendly lifestyle changes, such as recycling empty bottles and cans or turning your air conditioner up a couple of degrees, are relatively painless. Others, such as bicycling to work, require more sacrifice and sweat. Especially when you have to share the road with drivers who don't appreciate your efforts to reduce your carbon footprint.

Reducing the amount of mail you receive from your bank, brokerage firm and other financial institutions should fall into the painless category, particularly if you already do your banking online. Receiving your bills and account statements electronically reduces fuel consumption and saves trees, and it usually doesn't cost you anything.

Yet while more than half of U.S. households bank online, most people still receive their bills and account statements in the mail, according to a new report by Javelin Strategy and Research, a consulting firm. Only 15 percent of households surveyed said they received their bank or credit union checking account statement "only online," and only 11 percent said they had eliminated paper delivery of their primary credit card bill.

If all U.S. households viewed and paid their bills online, Javelin says, the reduction in paper would save 16.5 million trees a year.

Mutual fund giant Vanguard Group waives its $20 annual account fee for customers who receive their statements, reports and fund prospectuses electronically. And a growing number of "virtual" banks — online banks that don't have bricks-and-mortar branches — are paying interest rates of 5 percent or more on savings accounts, compared with less than 1 percent for most traditional passbook savings accounts.

A few banks have promised to make donations to environmental groups if customers go paperless. But most financial institutions haven't promoted the idea that "turning off the paper" is a green thing to do, says James Van Dyke, president of Javelin.

There are a couple of reasons people who use online banking continue to receive paper statements: