WASHINGTON -- NASA will host a seminar at 11 a.m. EST, Friday, Nov. 14, to discuss the current state of knowledge about how the "breathing" Earth influences current and future levels of carbon dioxide in the atmosphere. The seminar will take place in NASA Headquarters' James E. Webb Auditorium, 300 E Street, S.W., Washington. It will be carried live on NASA Television.

The Earth plays an important but complex role in how much carbon dioxide is in the atmosphere. While the amount of carbon dioxide produced by fossil-fuel burning and other human activities continues to grow worldwide, a significant amount of the greenhouse gas is absorbed by the ocean and plants on land. Scientists are actively trying to pinpoint where, when and how Earth removes carbon from the air in order to better forecast future levels of the gas that is a major contributor to global warming. Better understanding Earth's "carbon cycle" is a key element of NASA's Earth science program.

The seminar participants will be:

- Scott Denning, carbon cycle scientist, Colorado State University, Ft. Collins

- Anna M. Michalak, carbon cycle scientist, University of Michigan, Ann Arbor

- William Emanuel, program manager, NASA's Science Mission Directorate, Washington

The seminar will also be broadcast live on the Web at:

http://www.nasa.gov/ntv

For more information on NASA's Earth science program, visit:

http://nasascience.nasa.gov/earth-science