This novel way to measure carbon dioxide produced by burning coal, oil and natural gas will help atmospheric scientists better understand where pollution is located and how it mixes and moves in the air. Tracking fossil-fuel-emitted carbon dioxide will be important as countries throughout the world adhere to the Kyoto Protocol, an agreement among nations to reduce greenhouse gas emissions. The United States signed the protocol, but the treaty has not been ratified by the U.S. Senate.
"Many nations are facing increasing pressure to monitor and regulate the release of carbon dioxide from fossil fuel sources to limit greenhouse gas warming," said James Randerson, associate professor of Earth system science at UCI and co-author of the study. "This method can help determine how much fossil fuel carbon dioxide is coming from different regions."
The study appears Jan. 23 in Geophysical Research Letters.
Atmospheric scientists typically measure carbon dioxide by collecting air samples, but this is the first time fossil-fuel-emitted carbon dioxide has been mapped using plants. This new method may complement existing air sampling techniques because plants provide a cost-effective way to record average daytime conditions over several months. Plants take in carbon dioxide gas, from both background and fossil fuel sources, during photosynthesis, and it becomes part of the plant tissue.
In summer 2004, UCI scientists collected corn from farms and gardens in 31 states, including Hawaii and Alaska. They chose corn because it is widely grown and, as an annual plant, all of its carbon is derived from a single growing season. The scientists avoided pollution point sources such as highways and power plants to allow for mapping of regional patterns across different states. Back in
Source:University of California - Irvine