The Carbon Cycle (Week 4) - Post 2

The Carbon Cycle

          Carbon is a building block of life; it is a basic chemical component in all living and non living things. Carbon is highly important to scientists, not just because of the things it is part of, but because of the ways in which it moves around. The carbon cycle is the circulation of carbon atoms throughout the atmosphere, biosphere, hydrosphere, and geosphere. There are three main things to consider when studying the carbon cycle: the flow of the carbon cycle unperturbed, human perturbations of the carbon cycle, and the effect of these perturbations. Since the industrial revolution human carbon emissions have increased exponentially. With the help of the carbon cycle it is possible to prove that the increase of carbon in the atmosphere is a direct result of human emissions. Chemical data based on the chemical makeup of certain isotopes and oxygen align directly with the theory that recent rise in carbon is due to human activity, generally know of as fossil fuel burning, clearing forested land for agriculture, and cement making. With this extreme inflow of greenhouse gases, it is easy to assume that all of this carbon would remain in the atmosphere once emitted, however atmospheric data has determined that only about forty-five percent of human carbon emissions remain in the atmosphere. The reason for this is the carbon cycle. By analyzing data and looking at computer models, scientists found that the other fifty-five percent of the carbon released is absorbed and stored in plants, oceans, and rocks. With regards to the general carbon cycle, there are inflows and outflows that form feedbacks, which vary from fast cycles, that take place over a single year, to slow cycles, that can take hundreds of thousands of years to complete. Each year plant life, within the biosphere, exchanges carbon with the atmosphere to create a rise and fall of net stock of carbon in the atmosphere. The plants and forests all absorb and either store or convert carbon dioxide. This exchange of carbon between plants and the atmosphere is just one of the many exchanges that contribute to storage of increased carbon emissions. The other two main exchanges of carbon happens when the oceans absorb atmospheric carbon dioxide, and the way rocks store carbon for long periods of time. In present times all of these components of the carbon cycle are helping to stabilize the carbon in the atmosphere, however human emissions are still increasing, and there is no definitive data on whether or not the carbon cycle will continue to store and stabilize carbon inflows as they increase. 

          The carbon cycle is vital to the change in global climate temperature. Carbon dioxide is the temperature determining greenhouse gas. The more fossil fuels burned, forests cleared, and cement made, the higher the carbon emissions, and so the more the temperature increase. Current carbon cycle components create a buffer between human emissions and the atmosphere. This buffer dilutes the increased carbon by over half. Unfortunately these cycles are complicated and difficult to predict. Scientists do not know how the carbon cycle will hold up as emissions continue to increase. Based on millions of years of climate data, scientists know that the cycle will stabilize itself eventually. However, based on past records it has been determined that it will take hundreds of thousands of years in order for the climate to right itself again. The IPCC, the Intergovernmental Panel on Climate Control, states that current carbon emissions will contribute to a rise in temperature of one to four degrees this century, however, if the carbon cycle changes from stabilizing to amplifying, the climate could see an increase as much as double that.