Pittsburgh's "green" story may have started when residents were forced to give up their coal furnaces, an unpopular improvement of Mayor David L. Lawrence's first "renaissance."

Now, a new chapter in the "green" story is being written that could lead to yet a third renaissance.

Here's what has been achieved:

Pittsburgh is home to 17 certified "green" buildings -- third most in the nation behind Seattle and Portland, Ore. More than that number await certification. Green buildings are certified by standards of the U.S. Green Building Council, which rate buildings by energy efficiency, design for maximum use of natural light and air and the materials used.

A large assortment of riverfront parks and trails have been almost completely linked.

A half-dozen former brownfields -- former industrial sites -- have been cleaned and turned into housing and retail centers.

More than a dozen condominium and loft developments are under way or completed Downtown.

Three Rivers Park -- 13 miles of waterfront green space from the 31st Street Bridge to the West End Bridge to the Hot Metal Bridge -- is scheduled to be finished in time for Pittsburgh's 250th birthday in 2008.

At the same time, powerful groups have sprung up to push a "green" agenda.

In 1999, Mayor Tom Murphy established the Riverlife Task Force to start greening the riverfronts. The Heinz Endowments established the Green Building Alliance in 1993 to support environmentally wise construction, and, in 1997, it established a consulting group, Sustainable Pittsburgh. Friends of the Riverfront formed in 1996 and became a steward of rivers and trails.

Yet, despite these efforts, sprawl has defined the growth of the region for decades.

The third slowest-growing state, Pennsylvania is the sixth largest developer of land. Development of what had been natural environment grew by 47 percent between 1982 and 1997, while the state's population grew by just 2.5 percent, according to the Brookings Institution's 2003 report, "Back to Prosperity."

Gerrit Knaap, executive director of the National Center for Smart Growth Research and Education, said most cities have suffered population loss to suburban growth farther out on the perimeter.

"I don't see dumb growth going away," he said. "Smart growth is still the minority, but it's a niche that's growing."

In fact, the greening of Pittsburgh has converged with the smart-growth movement, which calls for the reuse of already-developed land and buildings, and design that favors pedestrians and mass transit over cars. Throughout the city and the region, forums on related topics have attracted a broad base of collaborators: people from foundations and universities, urban farming advocates, kayakers, bicycle and trail enthusiasts, designers and architects, ecologists, land-policy wonks, city planners, developers, transportation officials, neighborhood council members, preservationists and just neighborhood folks.

The pioneering urban-land planner and designer David Lewis, of West Homestead, said the current trend in the city has come from "decades of stirring."

The changes owe to a combination of forward thinking, a history of heavy pollution, and necessity, the same reasons for the Pittsburgh renaissance Mayor Lawrence is credited with starting in the 1950s.

"When I talk to reporters around the world who are surprised Pittsburgh is a leader in 'green' buildings, I present it as not so surprising," said Rebecca Flora, executive director of the Green Building Alliance. "In the '40s, we realized we were in a crisis of air and water pollution. We were a world leader in getting clean. Yes, it's exciting now, but we have a legacy.

Foundations in the lead

"Foundations took the initial risk," said Ms. Flora of the green surge in the '90s. The Heinz Endowments and Richard King Mellon Foundation have been credited with leading the way. "But this is very real, and it's where our country and the world is going. Now we need solid partnership with government."

The Heinz Endowments has contributed $9 million to $10 million a year to local projects since establishing environmental grants in 1993.

The Endowments sponsored the design competition for the David L. Lawrence Convention Center, the largest green convention center in the world; funded a study of steep hillsides that led to city guidelines controlling steep-slope development; and funded a collaboration between 10,000 Friends of Pennsylvania and the Brookings Institution to come up with a competitive agenda for the state.

Alan AtKisson, an international consultant on issues of sustainable development -- development that can sustain generations to come -- pronounced the Pittsburgh region in the midst of "a remarkable comeback."

He consulted with the city and the Heinz Endowments through the 1990s and graded Pittsburgh on a "sustainability index" in 2003.

"Overall," he wrote, "it showed steady and consistent increase over a decade. The overall score increased by seven points, from 57 to 64 out of 100 possible. That increase was reflected in every dimension" of the index: nature, economy, society, and well-being. While some things were better and some worse, the general direction was decidedly up."

More signs of green

Here are other examples showing that Pittsburgh, the region and the state are moving toward a greener future:

Pittsburgh recently joined the Cities for Climate Protection network and established a Green Government Task Force to monitor environmental performances of city properties and projects and prepare a local action plan for the city in time for the 2008 budget.

The first Pittsburgh Green Forum, on the North Side early this month, was devoted to solutions for vacant property. About 250 citizens turned out for the evening session and another 150 activists, planners and representatives from nonprofits the next morning.

Allegheny County is in the public input stage of creating its first-ever comprehensive land-use plan for 130 municipalities.

The state's planning board was reinstituted on the heels of Gov. Ed Rendell's Keystone Principles for growth, investment and resource conservation, a 10-point declaration of anti-sprawl sustainability.

The Keystone Principles echo the recommendations of the 2003 Brookings Institution "Back to Prosperity" report.

The report faulted Pennsylvania for having no strategies to keep or attract population or reinvest in old towns and cities and their older suburbs; and no strategies to contain sprawl. Marilyn Gelzhiser, a planner with Allegheny County's economic development department, said sprawl "is why multi-municipal planning is so recommended."

Although the county's comprehensive land-use plan will be largely advisory, it comes in response to "a push from the state toward sustainability," said Ms. Gelzhiser. "There's just been a great convergence of efforts."

"The Keystone Principles is the state gesturing to regions with expeditious ideas to get more bang for buck," said Court Gould, executive director of Sustainable Pittsburgh, which is involved in multi-municipal land use planning. "Dollars are scarce, expectations are high, principles of sustainable development are mainstream and our ticket to stability.

"This is a very exciting time to be in our region right now," said Mr. Gould. "What once might have been thought warm and fuzzy are prerequisites to a complete community that's more successful in the long haul."