Mexico and greenhouse gas emissions.

Mexico has experienced political strife throughout its history, including major wars and executions of leaders. The Spaniards invaded the region in 1519, conquering the Aztec and Mayan native cultures. Mexico attempted to declare independence from Spain in 1810, resulting in war and the execution of a number of leaders from Mexico. This war of independence lasted until 1821, when Spain finally granted Mexico its autonomy. The Mexico of 1821 included most of present-day Central America and the southwestern United States.