Which gas is a major greenhouse gas contributing to atmospheric warming?

Which gas is a major greenhouse gas contributing to atmospheric warming?

• A. Carbon Dioxide
• B. Water Vapor
• C. Oxygen
• D. Methane

Answer: (A)

Greenhouse gases trap heat in Earth's atmosphere by absorbing infrared radiation, warming the surface. Carbon dioxide is a major contributor because it is released in large amounts from burning fossil fuels and stays in the atmosphere for a long time, building up and enhancing the warming effect. Methane is more potent per molecule but exists in much smaller quantities and remains shorter in the atmosphere, so its overall impact is smaller than CO2 over the long term. Water vapor also adds warming, but its level depends on temperature and acts more as a feedback to warming rather than a sustained forcing. Oxygen doesn’t trap heat in the same way. So carbon dioxide stands out as a key gas driving long-term atmospheric warming.

Greenhouse gases trap heat in Earth's atmosphere by absorbing infrared radiation, warming the surface. Carbon dioxide is a major contributor because it is released in large amounts from burning fossil fuels and stays in the atmosphere for a long time, building up and enhancing the warming effect. Methane is more potent per molecule but exists in much smaller quantities and remains shorter in the atmosphere, so its overall impact is smaller than CO2 over the long term. Water vapor also adds warming, but its level depends on temperature and acts more as a feedback to warming rather than a sustained forcing. Oxygen doesn’t trap heat in the same way. So carbon dioxide stands out as a key gas driving long-term atmospheric warming.