Land-Use/Land Cover Change as Driver of Earth System Dynamics: past progress, future priorities, and new data and models for advancing the science

Abstract:

Human land-use activities have resulted in large changes to the biogeochemical and biophysical properties of the Earth surface, with impacts on climate. The activities which alter vegetation cover, biomass, and phenology, directly influence regional to global climate through modification of surface biophysical properties and the surface energy balance. Land-use activities are also impact climate through changes in carbon and nitrogen balances and greenhouse gas emissions. Moreover, land-use activities are likely to expand and/or intensify further to meet future demands for food, feed, fiber, and energy. The fifth phase of the Coupled Model Intercomparison Project (CMIP5) achieved a qualitative scientific advance in studying the effects of land-use on climate, for the first time explicitly accounting for the effects of global gridded land-use changes (past-future) in coupled carbon-climate model projections. Enabling this advance, the first consistent gridded land-use dataset (past-future) was developed, linking historical land-use data to future projections from Integrated Assessment Models, in a standard format required by climate models (“Land-use Harmonization”). Results from climate models indicate that the effects of land-use on climate, while uncertain, are sufficiently large and complex to warrant an expanded treatment of land-use. Here, we review past progress, future priorities, and present on new data and models designed to improve the understanding of the effects of land-use on climate (past-future). The work is organized through the Land Use Model Intercomparison Project (LUMIP) in preparation for CMIP6.