Greenhouse gases are the largest reason we are facing global warming today. These gases are depleting the ozone layer that blocks the suns UV rays, and Landfills are only adding to its affect. According to Liesch.com, "Landfills are considered the largest anthropogenic (caused by humans) source of methane (CH4) in the United States. Methane is one of the major greenhouse gases. 2) Landfills produce additional greenhouse gases including carbon dioxide (CO2), nitrogen oxide (N2O) and perfluorocarbons (PFCs)" (C-Davies). The best way to tell whether or not a particular landfill is dangerous to the environment or not is to take its carbon footprint. This tells exactly how much it is effecting the earth, particularly the part it plays in greenhouse gas emissions.
A good way to lower greenhouse gas emission caused by landfills is to store toxic chemicals in container or "carbon sinks" so that the gases do not pollute the air. Another popular practice is the "Carbon Credits." Many large companies that dont use all of their credits trade their credits with others that need them. It is almost then evened out. One particular contributor to greenhouse gases gives out less carbon, and another makes up for what that company did not use (Liesch.com).
C. Davies. "Managing Your Landfill's Carbon Footprint." 4/1/2009. http://www.liesch.com/news/managing-your-landfill%E2%80%99s-carbon-footprint