In 2013, the Carbon Cycle Interagency Working Group (CCIWG) agreed to release an interagency solicitation for carbon cycle science. This solicitation was released by the National Aeronautics and Space Administration (NASA) through its annual Research Opportunity in Space and Earth Sciences (ROSES) call for proposals. The Department of Energy, NASA, National Oceanic and Atmospheric Administration, and U.S. Department of Agriculture collaborated to write the solicitation, review the proposals, and, ultimately make awards to successful proposals. See current awards [PDF].
Solicitation details can be found here and the solicitation can be found here