The republic of Mexico has a land area of 758,249 sq. mi. (1,972,550 sq. km.), a population of 106,535,000 (2006 est.), and a population density of 142 people per sq. mi. (55 people per sq. km.). About 12 percent of the country is arable, with a further 39 percent used for meadow or pasture (often for low-intensity grazing), and 24 percent of the country is forested. The climate of Mexico varies considerably; while some of the northern parts are arid desert, the central plateau is much colder, especially in winter, and the southern part of Mexico is largely tropical jungle. As well as the regional variations in climate, there have also been studies of Mexico’s climate over recent centuries. Many historians now believe that the Mayan civilization collapsed in about 950 c.E. as a result of lack of food supplies, possibly through an earlier episode of climate change. It coincided with a period of prolonged drought. This has led some global warming skeptics to suggest that both global warming and climate change are historical cycles, rather than solely a result of human activity.
Largely because of its heavy industry and the size of its population, Mexico has a high rate of carbon dioxide emissions per capita, at 4.5 metric tons per person in 1990, reduced to 3.9 metric tons per person by 1991, after which it rose slightly, to 4.24 metric tons in 1993. The vast majority of Mexico’s carbon dioxide emissions (73 percent) come from the use of liquid fuels, and 17 percent come from gaseous fuels. This is not just from the use of automobiles (transport makes up 27 percent of the country’s carbon dioxide emissions), but also from the proliferation of gasoline-driven generators. Approximately 75.9 percent of electricity in Mexico is generated from fossil fuels. For the remainder of the electricity production in the country (accounting for 31 percent of carbon dioxide emissions), 16.8 percent of the power comes from hydropower, and 4 percent from nuclear power. Mexico’s other major contributions to global warming are from cement manufacturing (4 percent) and gas flaring (1 percent).
The effects of global warming in Mexico have been marked in parts of the country. The Pacific coastline of Mexico has seen an increase in the numbers of tornados, and there is clear evidence of coral reef bleaching. In 1998, the country recorded its worst fire season on record up to that point, with fires destroying 1.25 million acres (505,857 hectares). The smoke from this triggered a statewide health alert in Texas. Pollution in Mexico City also remains particularly bad, with 4 million automobiles, 200,000 buses, 35,000 taxis, and 60,000 factories responsible for considerable carbon dioxide and sulfur emissions. Traffic congestion is serious throughout the day, and the city is located in a 70-mi.- (113-km.-) wide basin, which prevents the fumes from dispersing. In some parts of the country, there has been an increase in the number of rainstorms, which in turn has led to the prevalence of insect-borne diseases such as dengue fever, which had previously been limited to an elevation limit of 3,300 ft. (1,006 m.), but has now been found at 5,600 ft. (1,707 m.). Concern about climate change and global warming has led to more publicity for the Green Party in Mexico.
The Mexican government took part in the United Nations Framework Convention on Climate Change signed in Rio de Janeiro in May 1992. They signed the Kyoto Protocol to the UN Framework Convention on Climate Change on June 9, 1998, with was ratified on September 7, 2000, with it entering into force on February 16, 2005.
