What is the primary gas responsible for the greenhouse effect on Earth?

The primary gas responsible for the greenhouse effect on Earth is carbon dioxide. This gas plays a crucial role in regulating the planet's temperature by trapping heat in the atmosphere. When sunlight reaches the Earth, some of this energy is absorbed, and some is reflected back into space. Carbon dioxide, along with other greenhouse gases, absorbs the infrared radiation emitted by the Earth, preventing it from escaping into space and thus warming the atmosphere.

This process is essential for maintaining temperatures that can support life. While other gases like methane and water vapor also contribute to the greenhouse effect, carbon dioxide is particularly significant because of its long-term presence in the atmosphere and its increasing concentration due to human activities, such as burning fossil fuels and deforestation. The increase in carbon dioxide levels has been linked to climate change, making it a key focus in discussions about environmental science and policies aimed at mitigating global warming.