In an effort to more fully understand the role rangelands play in the the global CO2 cycle, the Rangelands Carbon Flux Project was initiated by The Agricultural Research Sevice (ARS) of the USDA. A Bowen ratio CO2 flux monitoring network was installed in central and western United States, with stations at 12 grasslands locations. The Bowen ration stations allow researchers to measure the exchange of CO2 between the surface and the atmosphere. Three stations located in grasslands areas of Central Asia are also contributing data to the project.