IF CO2 IS ONLY 0.04% OF THE ATMOSPHERE, WHY IS THIS GAS RESPONSIBLE FOR GLOBAL WARMING?

CO2 makes up only about 0.04% of the atmosphere. Why is this gas with such a low concentration in the atmosphere is crucial in the development of global warming?

During a global climate change protest demonstration strike. Image credit: Markus Spiske via Unsplash, free license

How does CO2 lead to climate change?

Carbon dioxide is naturally present in the Earth’s atmosphere as part of the carbon cycle. However, human activities such as burning fossil fuels, deforestation, and industrial processes have dramatically increased the levels of CO2 in the atmosphere.

Since the start of the Industrial Revolution, atmospheric CO2 concentrations have risen from about 280 parts per million (ppm) to over 415 ppm today, largely due to these activities. The long atmospheric life of CO2 means that even if emissions were reduced today, previously emitted CO2 would continue to affect the atmosphere for centuries.

This persistent increase in CO2 not only thickens the layer of greenhouse gases but also enhances their heat-trapping capability over extended periods.

CO2 and the greenhouse effect

Greenhouse gases, including CO2, are transparent to incoming solar radiation but trap heat radiating back from the Earth’s surface, thus warming the atmosphere. This process is similar to what happens in a greenhouse, where sunlight penetrates through transparent materials and warms the plants and air inside; however, the heat is trapped inside, leading to higher temperatures.

The natural greenhouse effect is critically important for life on Earth because, without it, the planet would be too cold for most forms of life. However, the balance of this system can be disrupted by excessive greenhouse gas concentrations, particularly CO2, leading to more heat being trapped than is typical.

When we burn fossil fuels such as coal, oil, and gas, CO2 accumulates and thickens the layer of greenhouse gases in the Earth’s atmosphere, exacerbating the natural greenhouse effect. This enhanced effect causes more thermal energy to be trapped by the atmosphere, leading to a gradual increase in Earth’s temperature.