CLASH – Climate-responsive Land Allocation model with carbon Storage and Harvests

Abstract. The Climate-responsive Land Allocation model with carbon Storage and Harvests (CLASH) is a global land-use model that can be embedded into integrated assessment models (IAMs). It represents vegetation growth, terrestrial carbon stocks, and production from agriculture and forestry for different land-uses in a changing climate; and hence, allows the inclusion of terrestrial carbon stocks, agriculture and forestry in global climate policy analyses. All terrestrial ecosystems and their carbon dynamics are comprehensively described at a coarse resolution. Special emphasis is placed representing the world’s forests. In CLASH, vegetation growth, soil carbon stocks, agricultural yields and natural disturbance frequencies react to changing climatic conditions, emulating the dynamic global vegetation model LPJ-GUESS. Land is divided into ten biomes with six land-use classes (including forests and agricultural classes). Secondary forests are age structured. The timing of forest harvests affects forest carbon stocks; and hence, carbon storage per forest area can be increased through forest management. In addition to secondary forests, CLASH also includes primary ecosystems, cropland, and pastures. The comprehensive inclusion of all land-use classes and their main functions allows representing the global land-use competition. In this article, we present, calibrate, and validate the model, demonstrate its use, and discuss how it can be integrated into IAMs.