Which gas contributes most to the greenhouse effect

Carbon dioxide gas contributes most to the greenhouse effect

Explanation:

The greenhouse effect occurs by human activities, such as cutting the forest and burning fossil fuel, which increases the level of carbon dioxide gas.

Burning fossil fuel results in the combination of carbon with oxygen which forms Carbon dioxide.

The Greenhouse gas  Carbon dioxide contributes the most greenhouse effect by trapping the radiating heat from the Earth,  heat is absorbed in form of radiations and emitted which warmer the lower atmosphere, resulting in  melting of glaciers,melting of ice sheets, and warming the ocean.

Thus Carbon dioxide gas contributes most to the greenhouse effect.