Landfills produce methane, which is a greenhouse gas and contributes to global warming.

A complex process of waste decomposition and fermentation under anaerobic conditions produces methane in the landfills. The amounts of methane depends of the characteristics of the waste, the operating of the landfill and the climate. Landfill gas is composed of roughly 50 percent methane and 50 percent carbon dioxide (CO2) and a small amount of non-methane organic compounds. Landfills are the third-largest source of human-related methane emissions.

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

c. heat from the poles back down towards the equator.