Joan Fitzgerald, urban planner, professor, and director of the Law, Policy and Society program in Northeastern’s College of Arts and Sciences, recently authored “Emerald Cities: Urban Sustainability and Economic Development.” The book extols the value of going green to drive economic growth in our cities. In this Q&A, Fitzgerald offers her perspective on best practices, examples of what cities can accomplish, and direction on policies that are needed for a post-fossil fuel economy.

As we celebrate the 40th anniversary of Earth Day, what do you see as the future of the sustainability movement? Are there issues on the horizon that we should we be working to combat now?
I think of the sustainability and climate change agenda together. There are many problems that we need to address. The most urgent is reducing oil consumption — this is critical for reducing greenhouse gas emissions, reducing other pollution associated with oil use, and increasing our energy security.

For cities, that means reducing vehicle miles traveled — getting people out of their cars and walking, biking or using public transportation. Energy efficiency is another area where we need to move more quickly than we have been — we can do this with existing technologies. And we need to be developing the clean technologies for the future. That will take a much bigger federal commitment than we have made so far.

Most people understand the concept of sustainability and green cities and support these initiatives in theory. What are the economic benefits for communities embracing green technologies and ideas?
This is the subject of my book — there are so many economic opportunities for cities focusing on sustainability and reducing greenhouse gases. A lot of people have heard about Chicago’s green roofs — as a result, a number of new companies that specialize in green roof construction have started up, providing new jobs.

Likewise, Portland, Ore., and Seattle are leaders in green building. Several of their architecture firms specialize in green building and consult all over the world. Toledo, Ohio, is building on its strength in auto glass production to build thin-film solar panels. Cleveland hopes to build wind turbines that can be used on Lake Erie. The Pittsburgh and Syracuse, N.Y., regions are transforming building supply industries into green building suppliers.

You have studied urban communities across the country. What are your favorite green cities?
My top green city is Los Angeles. It is a city that has a long way to go and is moving on every front —it has the nation’s largest building efficiency initiative, a plan to make solar energy a major part of the city’s energy supply, has a recycling rate that is close to 70 percent, has cleaned up its port and is building a major public transportation infrastructure. LA is moving on every front.

Portland is another one — the city has developed a street car and light rail system that has created a lot of economic development in the areas served by it, it is a leader in bicycle commuting and green building and is developing a renewable energy industry.

What national and state policies will work best to encourage a green economy?
We have to stop subsidizing the industries that contribute most to greenhouse gases and increase investment in renewable energy and other clean technologies. The energy bill has to put a price on carbon and implement a strong portfolio standard for increasing the amount of energy we get from renewable sources. The transportation bill has to focus more on public transportation and less on highways.