Fuelbeds vary widely in their physical attributes, potential fire behavior, and fire effects. As models that predict fire behavior, fire effects, and carbon cycling become more sophisticated and widely used, there is an increasing need to accurately quantify and classify the structural and geographical diversity of wildland fuels. The Fuel Characteristic Classification System (FCCS) was designed to represent the diversity of fuels found throughout North America and predict their relative fire hazard. FCCS version 2.0 builds on this system by predicting surface fire behavior and quantifying carbon stores for each calculated fuelbed.