Mayors from around the world signed a voluntary pact on Sunday in Mexico City to reduce greenhouse gas emissions at a meeting meant as a precursor to UN-sponsored climate talks in Cancun opening next week.

Each city “will have to register its climate data [commitments as well as performance] in the city climate record” during the next eight months, said Gabriel Sanchez, president of Think Foundation,

The Coalition is composed of mayors from both major political parties, the Progressive Party, and the Green Party,[8] and its statement of principles has received the endorsement of the U.S. Conference of Mayors and the National Conference of Black Mayors.

Mayors Against Illegal Guns was founded by New York City Mayor Michael Bloomberg and Boston Mayor Thomas Menino.