Carbon Tet

Carbon Tetrachloride In the Oceans

I’m McKensie Daugherty, your host for on the ocean. Global climate change is the result of more than just carbon dioxide in the atmosphere. Carbon Tetrachloride, also known as carbon tet, is a man-made compound, made up of one carbon and four chlorine atoms, and is known to play a part in climate change, by destroying the ozone layer. It is also a significantly more potent green-house gas then carbon dioxide. After it is released into the atmosphere, it can go to the stratosphere where the ozone layer is, soils, or the oceans where the large scale destruction occurs. In science, there is a mathematical way to quantify this process using a value that is unique for every compound and each specific path to destruction, called a rate loss constant. Back in the 90’s the countries from around the world collaborated to prevent future damage from Ozone depleting substances by enacting the international treaty called the Montreal Protocol. This effectively banned Carbon Tet and required its usage and emissions to be reported. So by using the reported emissions and the known rate loss constants for each place of destruction, scientists have predicted there to be about a 4% per year decrease in atmospheric Carbon Tet concentrations. However, it was observed that it is decreasing at a rate of only about 1% per year. Scientists at Texas A&M University are trying to obtain a more accurate value for the rate loss constant for the ocean, since many components of this value are still unknown. Hopefully, this research will lead to closing the gap between the expected decline, and observed decline of this dangerous compound from the atmosphere. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professor: Dr. Shari Yvon-Lewis

Contributing Graduate Student/Author: Stanford Goodwin

ccl4 lifetime graph

Hemispheric concentrations since the early 1900’s.

ccl4 decline graph

Concentration after the Montreal Protocol

ccl4 rate loss

How the rate loss for the ocean is calculated mathematically.