It wasn't always this way in Salt Lake City. For more than a century, Utah was supported by the wealth derived from mining, ranching and energy — industries intent on exploiting, not conserving, the state's natural bounty. Those advocating green values were viewed as a threat to expansion and prosperity.

But Utah's population, now around 2.5 million, is expected to grow to 5.4 million by 2050. Traffic congestion, the loss of open space to suburban development and water pollution along the Wasatch Front, where 75 percent of Utah's residents live, have become public concerns. So have the high cost of housing and general anxiety about a deteriorating way of life.

These days, advocates for the conventional fixes to growth — more highways, more malls, more subdivisions ever farther from town centers — find themselves on the defensive in public hearings. Now there is a different strategy that involves doing more with less: less land, less energy, less asphalt, less spending.

Examples in the Salt Lake Valley are not hard to find. Kennecott Copper is starting a new community at the foot of its gigantic Bingham open-pit copper mine; it is designed to use less energy and less land and to put its residents closer to schools, stores, offices and recreation. Voters last year approved a sales-tax increase for a light-rail line that will tie the community, named Daybreak, to Salt Lake City.

But Keith Bartholomew, an assistant professor of planning at the University of Utah's College of Architecture and Planning in Salt Lake City, said the region had a long way to go. "Our successes mean it's not going to be as bad as it would have been," he said. "But doing less bad is not enough. We need to multiply the successes, and we need to do it fast. The nest we are soiling is not just the environment. It's the economy, too." An example of the half steps Bartholomew spoke of is a proposed $1 billion, 14-mile freeway, which critics argue will cause more congestion and wreck wetlands along the Great Salt Lake. Two years ago, the state's Department of Transportation settled a lawsuit with suburban residents, and under the agreement, the state will trim the number of lanes, prohibit billboards, protect natural lands, ban trucks, limit speeds to 55 mph, require the state to establish a 2,225-acre nature preserve and restrict development so the highway serves as a scenic parkway.

Residents are also voting to spend tax money on alternatives to highways and land conservation. If all goes according to plan, when construction is finished by 2015, the region will have spent roughly $3 billion to build a 45-mile light-rail system and an 88-mile regional commuter-rail network.

The two-term mayor of the city, Rocky Anderson, a Democrat, has shaped much of Salt Lake City's administration and economic policy around reducing emissions of gases that cause climate change.