How do automobiles contribute to air pollution in Mexico City?

Mexico City’s air quality is significantly impacted by its massive fleet of approximately four million automobiles, which serve as a primary source of air pollution in the capital. These vehicles emit pollutants such as nitrogen oxides and carbon monoxide, which are common byproducts of fossil fuel combustion.12

The environmental impact of these emissions is exacerbated by the city's geography and climate. Mexico City is situated in a basin surrounded by mountains that limit air circulation. This natural confinement, combined with temperature inversion—a phenomenon where a layer of warm air traps cooler air near the surface—prevents pollutants from dispersing, effectively creating a blanket of smog over the city.3

While the government has attempted to mitigate this by restricting vehicle use based on license plate numbers, these efforts have been partially undermined by wealthier commuters purchasing additional vehicles to bypass the regulations.1