The Washington Post

By Mike Tidwell

On the 40th anniversary of Earth Day, what environmental legislation should we celebrate most? What bill has really stood tall for our fragile planet? The Endangered Species Act of 1973? The Clean Air Act of 1990? Or … the District of Columbia’s plastic bag tax of 2010?

Actually, despite my gratitude for healthy lungs and spotted owls, I would vote for D.C.’s brand new 5-cent tax on plastic bags. The concepts behind this local municipal bill, believe it or not, are the best tools we now have for saving our global environment, including solving the crisis of climate change.

Need proof? First, since taking effect Jan. 1, the D.C. bag tax has been wildly successful. At pharmacies, grocery stores and carry-out joints across the capital, plastic bag use has dropped more than 80 percent, according to the city, from roughly 22.5 million per month to 3.3 million. And since half the physical pollution in D.C.’s ailing Anacostia River is comprised of plastic bags, the positive impact has been immediate and staggering. Store owners, meanwhile, are mostly happy since they no longer have to purchase and give away millions of bags. The stores save money.

But how have customers managed to go nearly cold turkey on plastic? Easy: They are finally bringing reusable bags to the store. My wife, who shops frequently in D.C., now has a reusable cloth bag permanently stuffed in her purse, one in her car, and even one in her umbrella. The same goes for most people in the D.C. region. Or people just do without. Who really needs the automatic plastic bag for that one bag of chips, anyway? Just use your digits.

Final result: Plastic bag use has dropped so much in the District that it has stunned even environmentalists, creating an inspiring success story for Earth Day 2010.

But here’s the more important question: Why have D.C. consumers made these changes? It’s just a nickel tax per bag, after all. Well, it turns out, people really, really don’t like paying extra money for stuff. The “price signal” is an extraordinarily powerful tool, economists remind us. In D.C., that price signal has simultaneously educated consumers about a local ecological problem, providing a moral motivation for many people. I’m a professional environmentalist, for god’s sake, but I only got serious about reusable bags with the help of a tax and a wife who now won’t let me leave the house without a lecture and a cotton bag tossed my way.

It’s a fact of life: Changing people’s behavior, changing their ingrained habits, is very, very hard. But the D.C. bag tax has done it, moving people away from a negative environmental behavior and toward a positive one. It’s done so quickly and on a mass scale. As a bonus, the money collected from D.C.’s bag tax goes directly toward other cleanup efforts along the Anacostia River. The Baltimore City Council, meanwhile, should emulate D.C., adopting a proposed plastic bag tax but using the money for ecological programs, not for balancing the city budget.

So, how can D.C.’s success with little plastic bags have any connection to the larger and more important issue of global warming? The answer involves that key phrase, “price signal.” The D.C. law has shown that the cost of a product can induce wholesale ecological change within a population of 600,000 people.

Now, with the Greenland ice sheet melting and sea levels rising, why stop there? This Earth Day, it’s our job to think of the global atmosphere as one giant Anacostia River, clogged not with plastic bags but with horrific amounts of heat-trapping carbon dioxide produced by the combustion of fossil fuels. If you wanted to clean up this atmospheric river in a hurry, if you wanted people to use much less oil and coal and seek readily available alternatives like wind power and hybrid cars, what could you do? What policy might bring rapid behavior change? Hmmm?

Turns out there’s a great bill, right now, in the U.S. Senate that would produce a fair and effective price signal for fossil fuels, thus solving the problem. The bipartisan “CLEAR Act” would create an extra fee for the consumption of things like coal-fired electricity and gasoline. But the bill would rebate that fee back to all American households in the form of a monthly “carbon refund” check. We’d automatically use less dirty energy, thanks to the rising price of such fuels, but we’d be protected economically as the fee or “tax” is recycled back to us. It’s a brilliant idea and a brilliant piece of legislation, and it deserves to be passed by Congress this year.

What better way, after all, to mark the 40th anniversary of Earth Day than to actually save the Earth itself?