AP BIOLOGY

Detailed explanation-1: -Greenhouse gases include carbon dioxide, methane, nitrous oxides, and water vapor. (Water vapor, which responds physically or chemically to changes in temperature, is called a “feedback.") Scientists have determined that carbon dioxide’s warming effect helps stabilize Earth’s atmosphere.

Detailed explanation-2: -Carbon Dioxide Emissions. Carbon dioxide (CO2) is the primary greenhouse gas emitted through human activities. In 2020, CO2 accounted for about 79% of all U.S. greenhouse gas emissions from human activities.

Detailed explanation-3: -Greenhouse gases that occur both naturally and from human activities include water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and ozone (O3).

Detailed explanation-4: -Carbon monoxide (CO) is not considered a direct greenhouse gas, mostly because it does not absorb terrestrial thermal IR energy strongly enough.

Detailed explanation-5: -Carbon dioxide is called a greenhouse gas because it is one of the gases in the atmosphere that warms the Earth through a phenomenon called the greenhouse effect. Carbon dioxide molecules in the atmosphere absorb long-wavelength infrared energy (heat) from the Earth and then re-radiate it, some of it back downward.