Greenhouse Gases and Global Warming

Steps:

• Identify gases in the carbon cycle: carbon dioxide (CO2), methane (CH4), and oxygen (O2).
• Recall that global warming results from greenhouse gases trapping heat in Earth's atmosphere.
• Check which gases act as greenhouse gases: CO2 and CH4 absorb infrared radiation, while O2 does not.
• Select the option listing only the contributing gases.

Why B is correct:

• CO2 and CH4 are greenhouse gases that trap heat via the greenhouse effect, increasing atmospheric temperature as defined by radiative forcing principles.

Why the others are wrong:

• A: Excludes methane, which also contributes significantly to warming.
• C: Includes oxygen, which is not a greenhouse gas and does not trap heat.
• D: Excludes carbon dioxide, the primary driver of human-induced warming.

Final answer: B