What a rare moment in New York’s history. In about 15 years, we have moved from being a city considered ungovernable to a city that can now aspire to be “the first environmentally sustainable 21st-century city,” to use the Mayor’s own words.

In introducing a breathtaking plan that combines economic growth with environmental responsibility over the next quarter-century, Mr. Bloomberg and his team have demonstrated the kind of vision and ambition that is so often lacking in traditional politicians. Why didn’t Mr. Bloomberg’s predecessors—Ed Koch, David Dinkins and Rudolph Giuliani—produce a similar blueprint? While it’s true that Mr. Giuliani, for example, inherited a city that was down at the heels, and was rightly preoccupied with reversing decline and restoring our economic and psychic health, he certainly had the human capital—New York is filled with talented people, after all—to put together a similar forward-thinking agenda.

In any case, New Yorkers should be glad that we now have a Mayor who is identifying and anticipating future needs, rather than waiting for crises to occur.

By the year 2030, New York City’s population is expected to grow by a million—yet another sign of the city’s astonishing renaissance. But the city is relying on old infrastructure systems; the Bloomberg plan highlights the need to invest in new systems. It is one thing to plan for such growth; it is quite another to incorporate environmental priorities into those plans. For too long, economic growth and environmentalism were considered opposing goals with very different priorities. Mr. Bloomberg’s plan is visionary in many ways—not the least for the ways in which he has shown how a city can be green even as it grows.

Among the initiatives are a call to eliminate the city sales tax on hybrid cars—are you listening, President Bush?—a new emphasis on bike paths, and a delightfully creative proposal to use mussels to purify the East, Harlem and Hudson rivers.

In addition, the plan calls for an expansion of parks and playgrounds, the planting of a million trees in the five boroughs, and a rezoning program that would help to build homes for all those new New Yorkers.

The most controversial part of the plan is the Mayor’s push for a congestion tax of $8, to be paid by motorists who wish to enter midtown Manhattan at peak hours. London already has such a plan in place, but as former Transportation Commissioner Sam Schwartz pointed out the other day, New York had the idea first. Previous administrations couldn’t get it passed. This one, however, seems to have the muscle and vision to get it done. While the State Legislature is already revving its engines to block this proposal (and, in general, to give the Mayor a hard time), we trust that Governor Eliot Spitzer—unlike George Pataki—understands the deep impact that the city’s well-being has on the state, and that he will use the stature of his office to help Mayor Bloomberg’s vision become reality.

The details of Mr. Bloomberg’s plan will be debated in the weeks and even years to come. Not everything will come to pass; some will require lots of arm-twisting. But the Mayor has started a conversation about nothing less than the future of this city.