What is the main contributor to the greenhouse effect?

The main contributor to the greenhouse effect is carbon dioxide. This gas plays a critical role in trapping heat in the Earth's atmosphere, which is essential for maintaining the planet's temperature. Carbon dioxide is primarily released through human activities such as burning fossil fuels, deforestation, and industrial processes. Its concentration in the atmosphere has been increasing significantly since the Industrial Revolution, consequently enhancing the greenhouse effect and leading to global warming.

While water vapor is also a significant greenhouse gas and can contribute to the greenhouse effect, carbon dioxide is unique because it remains in the atmosphere for a much longer duration and its levels are significantly influenced by human action. Ozone, although a greenhouse gas as well, is most effective in the stratosphere where it protects the Earth from harmful UV radiation rather than contributing to the greenhouse effect in the lower atmosphere. Aerosols, on the other hand, generally have a cooling effect because they reflect sunlight away from the Earth, although they can also have warming effects in some cases.

Consequently, carbon dioxide's long-lasting presence and substantial increase due to anthropogenic factors make it the main contributor to the greenhouse effect, which is driving current climate change trends.