Mayor Daley has so carefully cultivated his ecofriendly image—he’s the rust-belt mayor who installed a garden atop City Hall!—that not even his critics question his commitment to going green. But maybe they should.

Several of the biggest controversies of Daley’s 20-year reign have environmental implications, including his decisions to let Wal-Mart into the city, expand O’Hare, and privatize the parking meter system. Yet no one has really asked how these policies square with his highly publicized quest to make Chicago the greenest city in America.

Take the parking meter deal. During the abbreviated debate before the City Council approved it, and even during the outcry that followed, there was very little discussion about how parking policy, and the city’s right to control it via the parking meter system, might affect driving patterns, and, consequently, greenhouse gas emissions.

To be fair, this sort of shortsightedness isn’t a purely local phenomenon, or a governmental one. Journalist and author David Owen says most of us have been lulled into believing we’re just a few rooftop gardens, hybrid cars, and locally grown meals away from having this environmental thing licked, when a real solution, the kind that might still avert catastrophe, is going to require radical shifts in our thinking and culture. “Something—many things—will have to change, in most cases sooner rather than later,” Owen writes in his provocative new book, Green Metropolis: Why Living Smaller, Living Closer, and Driving Less Are the Keys to Sustainability. “The cherished secret hope of most Americans—that some sudden technological breakthrough will enable our children and grandchildren to live the way we live now, except with smaller cars and larger recycling bins—is patently a fantasy.”

With Green Metropolis, Owen, a staff writer for the New Yorker, is intent on bringing us back to earth and all its ecological troubles. And he particularly wants to give us a close look at New York City, which he argues (sorry, Mayor Daley) is the greenest burg in the U.S.

Most green rankings put Chicago and New York well behind places like Seattle and Portland. But Owen says Gotham stands out in real measures of sustainability. If it were a state, for example, it would rank 12th in population but 51st in per-capita energy use. New Yorkers are concentrated, occupy relatively small spaces, minimize driving, and as a result consume far less fossil fuel than most other Americans.

The lesson, Owen says, is that sustainability is linked to population density, public transit, and structural efficiency. And if that’s the case, sprawl is the enemy.

“Every new outlying subdivision, every new corporate campus, every new shopping mall has pulled the city’s mantle of infrastructure farther from the core, and, in doing so, has massively increased duplication and waste, along with per-capita energy consumption and production of pollutants, including greenhouse gases,” Owen writes. “And all of that low-density growth has been driven and sustained by cars.”

Owen stresses that there’s no way out of this mess except to slow the rate of sprawl. Suburban and exurban commuters can trade in their SUVs for hybrids, but their improved gas mileage won’t make up for the fossil fuels used to build more police stations and sewer lines and Targets way outside the urban center. As Owen puts it, “the critical energy drain in a typical American suburb is not the Hummer in the driveway; it’s everything the Hummer makes possible—the oversized houses and irrigated yards, the network of new feeder roads and residential streets, the costly and inefficient outward expansion of the power grid, the duplicated stores and schools, the hundred-mile commutes.”

The suburbs, of course, are an easy target. But Owen takes on some liberal pets, too, including many revered by Mayor Daley and other urban greenies. The U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) certification program has become a popular measure of sustainability in architecture; Mayor Daley’s Chicago Standard requires that new municipal buildings attain LEED certification, and just last month Chicago made headlines for having more LEED-certified structures than any other city. Owen maintains that the program is not only deeply flawed but counterproductive, “not a comprehensive, objective assessment of true environmental impact but, rather, a values-laden incentive system that encourages projects which adhere to a very particular view of the environment and, especially, to a very particular view of high-end real estate development.”

The LEED program, he argues, gives people the false impression that it’s prohibitively expensive to go green, and that certain costly but only marginally important features—such as solar panels, which earn a lot of LEED points while typically producing a tiny percentage of a building’s energy needs—have a bigger impact on carbon emissions than less sexy considerations like access to public transit.

Owen also challenges the claims of the local food movement (sometimes fewer greenhouse gases are produced by shipping a truckload of fruit cross-country than growing it nearby) and blasts pseudo-environmental traffic policies like car-pool lanes on the grounds that anything that makes driving easier or more pleasant is an incentive for bad behavior. He even critiques household recycling programs for enabling us to “relieve our gathering anxieties about the future without truly altering the way we live.”

But Owen never explains exactly how we should alter the way we live. We can’t very well unbuild the exurbs and highways that he blames for so much of the problem—and, great as it is, we can’t all live in Manhattan.

He’s also off the mark in suggesting that individual choices have no impact. It would be great to halt or reverse sprawl, but until that happens, and even after it does, switching from gas-guzzlers to hybrids might give us fewer emissions to contend with since more than a fifth of all U.S. greenhouse gases come from cars and trucks. Owen is right to point out that recycling, say, plastic bottles isn’t an antidote to our overconsumption of them in the first place, but he’s wrong to suggest that the solution doesn’t include reducing and recycling. The EPA just released a report that found that 42 percent of the country’s greenhouse gas emissions are linked to “materials management,” from extracting raw materials to manufacturing and disposing of products. Cutting down on emissions at every stage of that process would obviously make a difference. (Yet Chicago and many other cities still lack comprehensive waste reduction or recycling policies.)

But it’s about as practical to suggest a sudden and complete switch to hybrid cars as it is to suggest we raze the suburbs. After the unambiguous recognition that climate change is the critical environmental issue of our time, what’s required is sound public policy that provides incentives for decisions—both individual and collective—that are sustainable, and disincentives for those that aren’t. In other words, we need a way to ensure that the costs of emitting greenhouse gases, and the benefits of avoiding them, are worked securely into our economic system. The most comprehensive, viable ideas advanced so far are in the cap-and-trade concept, in which businesses buy and sell limited rights to emit, and the carbon tax. Most environmentalists and economists favor cap-and-trade, since it places firmer boundaries on emissions and lets the marketplace determine the price we pay for doing the wrong thing. The U.S. House has already passed a cap-and-trade bill, and the Senate is expected to take it up sometime in the next year.

Meanwhile, there’s no reason Mayor Daley and the City Council can’t apply sound environmental principles at the local level. They missed their chance with the meter privatization—the hike in parking rates could turn out to be a disincentive to drive (even if our officials didn’t think about it in those terms), but it would’ve made more sense for the city to do it and pour the proceeds into major public transit upgrades. The mayor and aldermen will soon get another opportunity to consider what it means to lead a green city. Sometime this fall the council is expected to discuss whether to let another Wal-Mart into the city. The company has a well-documented record of squeezing out local businesses and being an accessory to sprawl, if not an agent of it—though recently it’s been trying to burnish its environmental image by reducing product packaging and adding green features to its buildings.

The debate at City Hall will undoubtedly focus on jobs and wages, as it has here in the past, and if environmental concerns are even raised, expect Wal-Mart supporters to note that its one Chicago store, on the west side, has a lawn on the roof. But a real discussion about the kind of long-range economic development we want, and how it ties in with the ways people work, shop, and get around, would be worthy of the city leading the world in rooftop gardens.