How do you beat sprawl, reduce traffic, and curb global warming?

Remake the center city into a compelling place to live.

So said Seattle Mayor Greg Nickels, a champion of the environment who spoke Thursday in Atlanta to invited civic, business and elected leaders.

Nickels was the first in a series of guest speakers for Fifty Forward, a two-year Atlanta Regional Commission initiative to spur decision-makers and the public into planning the region 50 years into the future.

Nickels said cities need to attract families with great schools, a safe environment and a diversity of people and opportunities.

"The toughest choice of the commuters should be what color shoes to wear on the walk to work, not which highway do I get on," Nickels said.

For the first time in many years, Seattle and its in-town neighborhoods are experiencing an explosion of new development, with a dozen cranes dotting the skyline, Nickels said.

"There's been a good debate over how can we make growth work for our communities rather than how can we stop growth," he said.

Like metro Atlanta, Seattle struggles with how to pay for transportation improvements. And Atlanta, despite horrendous traffic delays that are second only to Los Angeles', actually has an advantage: MARTA.

In the 1960s and '70s, the Emerald City twice turned down federal funding for a heavy rail system. That money came to Atlanta instead. It wasn't until last December that Seattle launched a streetcar, which travels less than 3 miles round-trip. The city is building a light rail system to link to Seattle-Tacoma International Airport.

But Nickels is trying to drive change. He's proposed a 20-year, $1.8 billion transportation plan that will pay for transit, sidewalks, bikeways, trails, street and bridge repairs and trees. He proposes paying for it by raising property taxes, taxing businesses at $25 per employee and placing a 10 percent tax on commercial parking fees.

Atlanta Mayor Shirley Franklin invited Nickels, who spoke at The Arthur M. Blank Family Foundation's headquarters in Buckhead.

Franklin helped inspire Fifty Forward along with futurist Glen Hiemstra of Futurist.com, said Sam Olens, chairman of both the ARC and the Cobb County Commission.

"We need to look longer term," said Olens.

Among the visionaries are students of E. Rivers Elementary School in Atlanta, who responded to the ARC's request that they design "postcards to the future" for the campaign.

Franklin and Nickels are old compatriots.

It was Franklin who broke resistance among fellow mayors to Nickels' pledge in 2005 to reduce greenhouse gas emissions, Nickels said.

The Bush administration had chosen not to sign the Kyoto Protocol, an international treaty to reduce greenhouse gas emissions.

At the U.S. Conference of Mayors's environmental committee meeting in Chicago, mayors close to Bush opposed Nickels' climate protection agreement. Then Atlanta Mayor Shirley Franklin walked in the room.

According to Nickels, Franklin told the meeting, "Of course we're going to do this."

Nickels said Franklin "pretty much took the wind out of the sails of the opposition." More than 800 mayors have since signed the pact, representing 78 million Americans, Franklin said.

Tale of the two cities