Mexico City

You arrive in Mexico City, one of the largest cities in the world. A few years ago the skies looked like

this (click)

⁠

because of air pollution, but lately the city has more blue sky days because they have switched to cleaner energy sources and more people are using public transit instead of cars.

Large cities are often better at reducing greenhouse gases compared to suburbs and smaller towns because people in cities usually live much closer together in smaller spaces and are able to walk and use transit rather than drive.