What are greenhouse gasses? How does carbon dioxide enter the atmosphere? (Site 1)

1. Greenhouse gases are compounds that are able to trap heat in the atmosphere, keeping the Earth's surface warmer than it would be if they were not present. These gases are mainly carbon dioxide; metahne, nitrous oxide, and flourinated gases.

2. Carbon dioxide enters the atmosphere from animals and plants through the process of respiration and the burning of fossil fuels from industries.