the concentration of carbon dioxide (CO2) in Earth's atmosphere was approximately 0.0415% or 415 parts per million (ppm) by volume. However, please note that atmospheric CO2 levels are subject to change over time due to various factors, including human activities.
When compared to other major gases in the atmosphere, such as nitrogen (N2), oxygen (O2), and water vapor (H2O), carbon dioxide is present in much smaller concentrations. Nitrogen constitutes the largest portion of the Earth's atmosphere, accounting for approximately 78% of the volume. Oxygen follows, making up about 21% of the atmosphere. Water vapor is a highly variable component and its concentration can range from nearly 0% to about 4% depending on factors like temperature and location.
So, in terms of abundance, carbon dioxide is a relatively minor component of the Earth's atmosphere. However, despite its low concentration, CO2 plays a crucial role in the Earth's climate system due to its properties as a greenhouse gas.
Greenhouse gases, including CO2, have the ability to trap heat radiated from the Earth's surface and contribute to the greenhouse effect. This natural process helps to maintain a habitable temperature range on our planet. However, human activities, particularly the burning of fossil fuels and deforestation, have significantly increased the concentration of CO2 in the atmosphere. This enhanced greenhouse effect has led to concerns about global warming and climate change.
The significance of carbon dioxide lies in its capacity to absorb and re-emit thermal radiation, trapping heat in the Earth's atmosphere. It is more effective in absorbing certain wavelengths of infrared radiation compared to other gases like nitrogen and oxygen, making it a potent greenhouse gas. While water vapor is the most abundant greenhouse gas, its concentration varies greatly and is influenced by temperature and local conditions. Carbon dioxide, on the other hand, has a longer atmospheric lifetime and its concentration is influenced more directly by human activities, making it a focal point of climate change discussions.
It's important to note that the overall composition of the Earth's atmosphere is complex and includes various other trace gases and aerosols, each with its own significance and impact on atmospheric processes and climate.