Which gas released during combustion of fossil fuels is a major contributor to climate change?

Which gas released during combustion of fossil fuels is a major contributor to climate change?

• A. Carbon dioxide (CO2)
• B. Oxygen (O2)
• C. Nitrogen (N2)
• D. Hydrogen (H2)

Answer: (A)

Greenhouse gases trap heat in the atmosphere, changing Earth’s energy balance. When fossil fuels burn, carbon in the fuel combines with oxygen to form carbon dioxide, which is long-lived in the atmosphere. Because CO2 stays for centuries and accumulates with ongoing emissions, it becomes the primary driver of human-caused climate warming among these options. Oxygen is mainly consumed in the reaction rather than released as a greenhouse gas; nitrogen largely stays as inert N2 in the air; hydrogen from fuels forms water vapor, which does contribute to warming but acts more as a short-term feedback and isn’t released in the same long-lasting, accumulative way as CO2. So, carbon dioxide is the major contributor.

Greenhouse gases trap heat in the atmosphere, changing Earth’s energy balance. When fossil fuels burn, carbon in the fuel combines with oxygen to form carbon dioxide, which is long-lived in the atmosphere. Because CO2 stays for centuries and accumulates with ongoing emissions, it becomes the primary driver of human-caused climate warming among these options. Oxygen is mainly consumed in the reaction rather than released as a greenhouse gas; nitrogen largely stays as inert N2 in the air; hydrogen from fuels forms water vapor, which does contribute to warming but acts more as a short-term feedback and isn’t released in the same long-lasting, accumulative way as CO2. So, carbon dioxide is the major contributor.