Air, a mixed gas of several substances, makes up an important part of Earth’s atmosphere and is key for life? It is a combination of different gases, each beautiful and unique, that surrounds the planet and allows the processes that power life and moderate global climate: Two of the gases in the air that are particularly key to living organisms and the environment are oxygen and carbon dioxide. Knowing how gases mix in the atmosphere and with life on Earth helps us to grasp the balance that maintains Earth as a habitable planet.
The Composition of Air
In Earth’s atmosphere, nitrogen accounts for 78%, oxygen 21% and -minor percentages of other gases. It contains 0.93% argon, 0.04% carbon dioxide, and other gases, such as neon, helium, and some others that simply exist in fewer quantities. The composition of the atmosphere can vary slightly with location, elevation, and environmental conditions, so it is not a rigidly fixed entity. But the top two, the two most important gases, oxygen and carbon dioxide, they are fundamental to life processes and global systems.
1. Oxygen (O₂)
Oxygen is one of the most recognizable and important elements to air. It comprises roughly 21 percent of the Earth’s atmosphere and it’s vital for the existence of aerobic organisms, including humans. Oxygen is an essential element for respiration, where cells use it to transform nutrients into energy. Oxygen is used and carbon dioxide is released as a waste product in this process.
Role in Respiration and Life
In humans and other animals, oxygen is inhaled through the lungs, diffuses into the bloodstream and then circulates to cells across the body. There, it is utilized in the mitochondria for the biosynthesis of adenosine triphosphate (ATP), the molecule responsible for supplying energy for cellular activities. Unless you have rocket-energy, there isn’t enough energy to grow a rocket without oxygen, so the organism dies.
Plants also require oxygen at night for respiration, although they also generate oxygen during the day through photosynthesis, which converts carbon dioxide and sunlight into oxygen and glucose.
2. Carbon Dioxide (CO₂)
This includes carbon dioxide, which, while less abundant than oxygen, is equally important in the functioning of the Earth’s ecosystems. Carbon dioxide, a gas comprising about 0.04% of the atmosphere, is a product of respiration in organisms, burning fossil fuels, and natural phenomena, such as volatile eruptions.
Role in Photosynthesis
Carbon dioxide is an important building block of photosynthesis, the process through which plants, algae, and some bacteria turn light energy into chemical energy. In photosynthesis, plants take carbon dioxide out of the air, mix it with water, and, with help from the sun, make glucose and oxygen. It is fundamental to the food chain, because plants are the foundation for almost all ecosystems, propelling energy to herbivores and (in turn) carnivores.
Impact on Climate
Carbon dioxide forms a major greenhouse gas that is critical for life processes. Greenhouse gases hold heat in the Earth’s atmosphere, helping keep temperatures where life can flourish. Despite that, there is a direct correlation between the burning of fossil fuels which releases carbon dioxide into the atmosphere, and global warming and climate change. Too much CO₂ in the atmosphere causes the greenhouse effect; hence, we have rising temperatures, melting ice caps and severe weather changes.
3. Other Gases in the Atmosphere
While oxygen and carbon dioxide are the most frequently discussed gases with respect to life, the air contains a couple of other gases that help facilitate the workings of the atmosphere. Nitrogen, for example, is the most plentiful gas in the atmosphere, but its inert nature renders it irrelevant in respiration or photosynthesis. It plays a key role in establishing the conditions that maintain stable amounts of gases in the atmosphere, including oxygen.
An inert noble gas, argon is present at a very small percentage in air and plays no role in biology. But it is commonly found in many industrial applications. Trace gases like neon, helium, and methane are also found in trace amounts, but can play significant roles in science and industry and technology.
The Importance of Air Quality
Air quality is fundamental to human health and environmental sustainability, as well as all life on Earth. Substances such as particulate matter, nitrogen oxides, sulfur dioxide, and ozone can negatively affect human health when inhaled, resulting in respiratory diseases, cardiovascular diseases, and premature mortality by contributing to the local and global increase in air pollution. In addition, air pollution can harm ecosystems, disrupt agriculture and contribute to climate change.
Efforts to diminish emissions, pursue clean energy, and conserve natural environments are necessary in order to keep the air we breathe, clean and healthy. Through carbon footprint reduction and maintaining the atmospheric balance, we can be responsible for the sustainable future of the planet.
Conclusion
Air — the mixture of gases that composes the Earth’s atmosphere — is essential to life. Oxygen is the element necessary for respiration and energy production, whereas carbon dioxide is necessary for photosynthesis and regulating the climate of the planet. Human activities can alter the balance of gases in the atmosphere, creating problems for the environment and health. Knowing how gases such as oxygen and carbon dioxide act in the atmosphere helps us better understand how the systems that support life on Earth are interrelated and how we can preserve our environment for future generations.
