YOUNG: Slow cities are, by definition, small cities. Some big cities are making environmental progress, too. By rethinking how people get around. Mexico City’s Metrobus project has cut CO2 emissions by an estimated 80,000 tons a year. Living on Earth reported on Metrobus when it started up in 2005.

JEFF: We spoke with former city environmental minister Claudia Scheinbaum.

SCHEINBAUM: We have substituted 350 buses for 80 buses, and the 350 buses used to be very old buses, so you have reduction in both in local pollutants and greenhouse gas emissions.

YOUNG: Mexico’s Metrobus was just honored by Harvard University’s Kennedy School of Government for its success. That’s where Living on Earth’s Steve Curwood caught up with Mexico City Mayor, Marcelo Ebrard. The mayor has ambitious plans to green the world’s largest cities.

CURWOOD: You’re off to Copenhagen. The 40 largest cities in the world, I believe, have come together, and a group of you mayors will be there. What do you expect to accomplish in Copenhagen as a mayor?

EBRARD: Well, we want to have an agreement between the most important cities of the world. And then to propose and to pressure the national governments and the global institutions to go faster than they go right now. And based in the effort that the cities already are doing. You take a look at Toronto, even New York, or San Francisco, or London. Every city in the world, the mayor part of them, are taking measures seriously, and fastly. And this is a global issue, so we cannot wait for the national governments to take the initiative because they are behind right now.

CURWOOD: So, what do you do to get national governments to move? What do you do to get your own government to move?

EBRARD: Well, we are pressuring every time to the government in our own country. I think that they understand that they should move faster. And we have an agreement because our plan in the city requires national decisions, for instance, what about the diesel? What about the car industry technology?

Should be a national-level decision, but the city have taken several measures in the past two years that move or pressure the federal government to move faster. For instance, we are going to have in Mexico City in 2011 the electrical cars from Japan and maybe, maybe United States. Maybe, I don’t know. So, this requires a new kind of decision from the federal level in order to supply the energy to the users of those cars, and to improve the regulations about the car industry technologies in Mexico. So, we are going to do this, at the same time the United States, UK, and the Canadian cities. So, it’s going to be a really important pressure to change the regulations in all those countries.

So, as far as I can see, the cities can lead these kind of decisions and really change things in the short term. Because, otherwise, we are going to wait – what, another five years? So, what’s going to happen?

CURWOOD: Now, if you look at the political spectrum, you’re considered more progressive, more to the left than your national government at home, which is considered to the right, more conservative. How do you overcome that gap, to get cooperation on these things?

EBRARD: So, we are talking to the young people, to the middle classes, also. In order to put these green issues at the top of the agenda and it’s working out.

CURWOOD: Recently, I think you increased the number of days you can’t drive a car. You started to include Saturday, so that means that in any given Saturday, what a fifth of your voters are unhappy with you.

EBRARD: Well, you know, 80 percent of the people in the city uses right now public transportation facilities – 80 percent. So, it’s very different the situation in Mexico City than here. But, on the other hand I think that if you really want to do things – several times you take positions there are no popular measures, but can be effective. So, you cannot only run the city with service in the short term.

CURWOOD: Some might say that you’re positioning yourself to run for president in 2012. That if the national government doesn’t perform, you’ll hold up Mexico City as a green example on other issues to bolster your candidacy for president – what do you say?

EBRARD: Yes, why not? Why not, we need more equal society in Mexico. And new ideas about innovation. Let’s think in the 21st century, and not the 1st century. So, why not?

YOUNG: Steve Curwood talking with Mexico City mayor Marcelo Ebrard.