When societies shift, one sign is the physical structures that they choose to tear down. Starting in late 1989, Germans reduced the Berlin Wall to rubble. In recent years, a depopulated Detroit has razed thousands of vacant houses. Now, the United States is starting to rip out dozens of old coal-fired power plants—a physical manifestation of what’s said to be a revolutionary lurch toward a cleaner global energy system.

The scraping of these coal plants is a response to three forces: cheap domestic natural gas, tougher environmental regulations, and rising public opposition to dirty coal. Studies predict that over the next few years this process of “decommissioning,” as it’s politely known, will shut down perhaps 20 percent of U.S. coal-fired power-generating capacity—and will balloon into a multibillion-dollar demolition business.

Fans of American coal’s comeuppance are giddy. Environmental groups trumpet the imminent demise of what they consider a filthy, outmoded fuel. The companies in the business of tearing down old cold plants—often the same construction firms that profited in a different era by building coal plants—are salivating over the profits they expect by riding the reversal in King Coal’s fortunes.

But booming markets seldom go as smoothly as their boosters hope. And the increasingly hot U.S. market for coal-plant tear-downs may not be the unalloyed financial or environmental victory that its most ardent proponents are claiming. In recent months, plans to tear down some coal-fired power plants have quietly been put on hold because their economics have soured. What’s more, even to the extent the U.S. continues to shut down old coal plants, other parts of the world are building newer, bigger coal plants even faster.

Coal has powered the global economy for more than a century—and, for all the hype about coal’s ostensible demise, to a large extent it still does. The percentage of the world’s energy that comes from coal has continued to rise—to 29 percent in 2011 from 23 percent in 2000, according to the International Energy Agency. The share of global electricity that comes from coal is even higher—41 percent in 2011, up from 37 percent in 1990, the IEA says. (Besides being burned in power plants, coal is used in various industrial processes—for instance, in some countries, to produce liquid transportation fuel.)