Americas Quarterly

Mexico City will literally take your breath away. Its traffic- choked highways and thick layer of smog are responsible for ozone levels that surpassed the World Health Organization’s recommended maximum 316 days in 2008.

However, things have actually improved in the nearly t wo decades since Mexico’s sprawling capital of nearly 21 million people was awarded the unfortunate distinction of being among the cities with the worst air pollution in the world by the the United Nations Environment Programme. Progressive environmental policies have sharply reduced the key contaminants in the air from their peak 1991 levels: lead has fallen by 96 percent; sulfur dioxide by 90 percent; carbon monoxide by 80 percent; and peak ozone levels are down 53 percent. Moreover, Mayor Marcelo Ebrard has promised to reduce the city’s greenhouse gas emissions by 15 percent by 2022.

One stepping stone toward that goal is dealing with the city’s overflowing garbage landfills.

This year the city launched, in conjunction with the Clinton Climate Initiative, a plan to build four waste treatment plants that will recycle, compost or burn 85 percent of the metropolitan region’s trash for energy. Construction of the $13 million plants was originally set for completion by 2012, but is currently delayed. What will surely advance that effort is the recent headline-making decision to outlaw the use of plastic bags by retailers—becoming the first major city in Latin America to do so.

Officials are also working to tackle Mexico City’s traffic jams, which remain notoriously unhealthy despite the Hoy no Circula (Don’t Drive Today) campaign enacted in 1989, which keeps cars off the road one day a week and reduces weekly traffic by an estimated 1. 6 million autos. One

example: a diesel-powered bus rapid-transit system that is expected to grow from its current 173-bus fleet to 700 in 2012—taking a cue from green transit systems in the region such as Bogotá’s TransMilenio and Curitiba’s Rede Integrada de Transporte—and will relieve pressure from the city’s stressed subways. The mayor, who famously bikes to work at least one day a month, announced plans in 2007 to add 186 miles (299 kilometers) of bike lanes to the city’s streets.

The thick brown haze that still hovers over the city suggests that authorities have a long way to go before matching, for example, the

success of Seattle, Los Angeles or Curitiba in achieving cleaner air. Overstressed municipal infrastructure and rapid population growth complicate environmental planning. And the city’s location on a high plateau, 7,400 feet ( 2,255 meters) above sea level and surrounded by even higher volcanic formations, creates a natural sink for trapping chemicals and other pollutants. But despite the geographic, structural and developmental challenges Mexico City faces, its success and ambition demonstrate the importance of municipal leadership and innovation.

—Danielle Renwick

Above: Is it safe to go outside? An air monitoring device on a Mexico City rooftop. Left: Clean yet? A used air filter from an air pollution monitoring center.