On his way to dinner Tuesday, Boston’s outgoing green czar James Hunt III suddenly gets distracted by the permeability of the pavement in front of a Dorchester restaurant. It’s fair to say he has been obsessed with the greening of Boston for the past seven years.

This week, Hunt stepped down from his Environmental and Energy Services cabinet post. The city’s all-around sustainability profile improved greatly under his watch. Mayor Menino accurately saw in Hunt someone with the technical and political skills to energize a sleepy department. And — crucially — the mayor gave his energy chief room to maneuver, even when Hunt placed green demands on the city’s developers. Had Menino balked, Boston wouldn’t be talked about in the same breath as San Francisco, Portland, and other cities that draw green industries. The city should view Hunt’s tenure as a model.

Menino wasted no time in naming Hunt’s replacement: Boston Properties project manager Brian Swett, an expert in green building construction. He should be expected to protect the city’s first-in-the-nation green zoning code that requires developers of projects larger than 50,000 square feet to undertake specific measures to conserve energy and reduce environmental impacts. When Hunt unveiled the code in 2007, Boston was finally a player in the urban sustainability movement.

Sue Reid, the director of Conservation Law Foundation Massachusetts, said Hunt is perceived in environmental circles as a leader with “thoughtful policy chops.’’ But he also enjoys a reputation as someone who will stick out his neck. In 2008, Hunt pushed the administration to demand that owners of almost 2,000 taxicabs — the entire fleet — switch to energy-efficient hybrids by 2015. A year later, a federal judge struck down the ruling. But by then, many cab owners had already embraced the idea that hybrids would be good for business.

Hunt’s most spectacular failure came last year in a showdown with Quincy officials. He had spent several years trying to convince them to accept a wind turbine on Moon Island, a property owned by Boston but located within Quincy’s city limits. The winds in Boston Harbor favored the project, as did state regulators. The two cities would have shared in the benefits of a project with the capacity to power 750 homes. But skittish neighbors worried about their water views. And Quincy officials backed out, even though the site was almost a mile from the nearest residence.

But there is already buzz in environmental circles about the possibility of building a similar turbine on Deer Island. Sooner or later, bold environmental initiatives seem to pay off in Boston. Many doubted the viability of the city’s Hubway bike-share program when it was announced last year. But it has been a huge draw for residents and tourists alike.

Hunt, who previously worked as an assistant secretary for the state’s Executive Office of Environmental Affairs, has served on high-level committees on climate change and greenhouse gas emissions. But his greatest contribution can be found in tangible projects like the no-cost home energy audits and low-cost insulation upgrades available through the city’s Renew Boston program.

“People need something they can see and touch,’’ said Hunt. Only then can city officials “build awareness and pride in a sustainable city.’’

Hunt, 40, leaves in the middle of a campaign to expand the use of solar energy in Boston. But having worked his entire career in the public sector, he said he is eager to “write my own job description in the private sector.’’ He’s smart to leave before he becomes a creature of City Hall.

There is plenty for his successor to do. Only about 100 homes and businesses in the city are outfitted with solar panels, but there is hidden demand for solar installations with minimal upfront costs and low, locked-in electricity costs. Also, Boston still posts poor recycling rates compared to cities with green reputations. And more must be done to increase recycling in dense neighborhoods with large numbers of renters than just distributing 32-gallon clear plastic bags inscribed with the mayor’s name.

Hunt gets credit for setting a goal to reduce the city’s carbon emissions by 25 percent by 2020. Unfortunately, city officials have taken to using the term “greenovate Boston’’ as shorthand for that effort. “Greenovate” should go; it’s an annoying phrase that trivializes an important goal. But Hunt’s ability to innovate will be missed.