A simple interactive vegetation model coupled to the GENESIS GCM

A growing number of research efforts have demonstrated the importance of climate–vegetation interaction in understanding climate sensitivity and climate change. In the study of Earth system history, vegetation is frequently specified or off-line vegetation calculations are produced using comprehensive biome models. However, these methods may fail to capture climate–vegetation feedbacks, and specified vegetation in a climate model may introduce substantial error into the simulation. Simple interactive vegetation models designed for incorporation into climate model studies in Earth history have considerable potential to (a) capture climate feedbacks ignored in earlier studies, (b) improve our ability to validate model simulations, and (c) gain greater insights into the distribution and character of vegetation in Earth history. The Simple Interactive Vegetation Model (SIVM) is a highly simplified vegetation model designed for Earth system history study. This model is evaluated by (1) determining the extent to which the simplified vegetation alters the simulation of the present-day climate, (2) determining the extent to which SIVM produces a realistic present-day vegetation distribution given observed climate parameters, and (3) examining the performance of the coupled GENESIS–SIVM system when applied to the Miocene and Oxygen Isotope Stage 3 climates. The SIVM provides substantial improvement over specified vegetation assumptions in climate models and aids in the interpretation of past climates.