Causes of Climate Change
What is carbon?
Carbon is an element that serves as the basic building block for all living organisms. On Earth, carbon can be found in plants, animals, rocks, water, and the air. In each of these places, carbon serves different functions and interacts with other elements to create many different types of molecules. For example, the carbon in the atmosphere binds with oxygen to create carbon dioxide gas, but carbon in the ocean can interact with calcium to form the shell of an aquatic creature. An individual carbon molecule will not always remain in the air, the ocean, or in the shell of a mollusk, however. Instead, individual molecules of carbon constantly change location between these different parts of life and the atmosphere on Earth. This movement of carbon is called The Carbon Cycle.
How does carbon move around?
There are several important ways that carbon moves between locations on Earth. The first is photosynthesis. When plants perform photosynthesis, carbon dioxide undergoes a chemical process that uses sunlight to turn carbon dioxide into sugars the plants use for energy. As a result of photosynthesis, carbon moves from the atmosphere to a new location. A similar process occurs as carbon moves from the atmosphere to plants, algae, and even as it dissolves in bodies of water.
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Next, plants are eaten and digested by animals. This process allows for carbon to become a part of these organisms.
Lastly, carbon can be released into the air or the ocean as animals digest food, as plants or animals perform respiration, or as the bodies of plants and animals decompose after death.
These are not the only ways carbon can move between the air, oceans, plants, animals, and rocks on Earth. However, events such as these are the basis of the carbon cycle.
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Does all carbon move around by way of the carbon cycle?
A simple diagram of parts of the carbon cycle, emphasizing the terrestrial (land-based) parts of the cycle. Credit: UCAR
Yes, all carbon participates in the carbon cycle, but not all carbon participates in the same way. Some carbon is trapped deep underground as fossils, fossil fuels, or sedimentary rocks. These form from deceased plants and animals after millions of years. This carbon cannot diffuse quickly into the atmosphere, and instead will move back into the air very slowly, over millions of years as rocks erode.
How does the Carbon Cycle relate to climate?
A well-functioning carbon cycle maintains a specific balance of carbon in the atmosphere(air, oceans,) and carbon in the biosphere (plants, animals.) It does this by removing carbon from the air and oceans at a rate which balances the speed at which carbon is released into the air and oceans. Because carbon dioxide is a greenhouse gas, the carbon cycle also has a critical influence on the temperature of Earth.
Greenhouse gases trap heat within the atmosphere. In the correct amounts, greenhouse gases ensure the survival of life on earth maintaining a livable temperatures on the planet.
How does the Carbon Cycle relate to Climate Change?
Humans have introduced a new way of travel for carbon that is trapped deep underground which is much faster than the processes of erosion by which this carbon would normally be released. This is the burning of fossil fuels. The world today relies heavily on the fossil fuels found in the ocean, such as oil and natural gas. When these fossil fuels are burned, the carbon quickly enters the atmosphere. In comparison to natural processes of erosion, burning fossil fuels is like a jump into light speed for the movement of carbon.
This increase in carbon in the atmosphere is not coupled by an increase in the ways, or the speed at which, carbon is absorbed. In fact, this increase in release of carbon is coupled with a decrease in carbon absorption. Since most carbon is absorbed by photosynthesis performed by plants, and today there are less plants around due to deforestation and industrialization, carbon absorption is hindered compared to what it would have been in previous centuries.
This burning of fossil fuels and deforestation started roughly 150 years ago when our ancestors began the Industrial Revolution. Since then, so much carbon has been released into the atmosphere that the entire temperature of the earth has risen over one degree Fahrenheit. The industrial nations are almost entirely dependent on using fossil fuels as a power source for society. Yet, the burning of fossil fuels releases carbon dioxide at life-threatening rates that the carbon cycle is struggling to support.
