Journal Article Research Support, Non-U.S. Gov't land-based mitigation negative emissions 142M471B3J 7440-44-0 BECCS Carbon Carbon Dioxide GHG emissions Soil afforestation agricultural expansion anthropocene avoided deforestation and afforestation biodiversity scenarios carbon dioxide removal carbon sequestration climate change mitigation cropland deforestation environmental impacts food security global environmental change integrated assessment land cover land use land use change land-use downscaling mean species abundance