Carbon dioxide (CO2) plays a significant role in the greenhouse effect, which is a natural process that warms the Earth’s surface. When the Sun’s energy reaches the Earth, some of it is reflected back to space and the rest is absorbed, warming the planet. The Earth then emits this energy back into the atmosphere in the form of infrared radiation.
However, not all of this outgoing infrared radiation escapes into space. Certain gases in the atmosphere, known as greenhouse gases, absorb and re-emit some of this energy. Carbon dioxide is one of the most important greenhouse gases, along with methane and water vapor.
When CO2 molecules absorb infrared radiation, they become energized and then re-radiate that heat in all directions, including back towards the Earth. This process traps heat in the atmosphere, keeping the planet warmer than it would be without these gases. This is what is commonly referred to as the greenhouse effect.
Human activities, such as burning fossil fuels, deforestation, and industrial processes, have significantly increased the levels of CO2 in the atmosphere. This enhancement of the greenhouse effect results in global warming and climate change, as more heat is trapped than ever before.