Final answer:
Burning trash at landfills releases greenhouse gases and toxins, which is a negative tradeoff. However, supporters believe the benefits of energy generation and reduced landfill use outweigh the environmental impact.
Step-by-step explanation:
One tradeoff to incinerating trash at landfills is that the act of burning trash releases greenhouse gases and other toxins into the air. Supporters of incineration argue that this drawback is outweighed by the benefits such as generating energy and reducing the volume of waste that requires landfill space. However, environmental concerns regarding the release of carcinogens and the increase in air pollution and smog must be taken into account. Incineration can help save space at landfills for garbage that cannot be burned, which can be seen as a benefit when considering the growing problem of landfill sites filling up and risking groundwater contamination.