Climate change is projected to be a powerful stressor on terrestrial ecosystems in the second half of the 21st century, especially under high-warming scenarios such as RCP6.0 and RCP8.5.

Direct human impacts such as land use and land use change, pollution, and water resource development will continue to dominate the threats to most terrestrial ecosystems globally over the next 3 decades. Changing climate exacerbates other impacts on biodiversity. Ecosystem changes resulting from climate change may not be fully apparent for several decades, owing to long response times in ecological systems.

Model-based projections imply that under low to moderate warming scenarios (e.g., RCP2.6 to RCP6.0), direct land cover change will continue to dominate over (and conceal) climate-induced change as a driver of ecosystem change at the global scale; for higher climate change scenarios, some model projections imply climate-driven ecosystem changes sufficiently extensive to equal or exceed direct human impacts at the global scale.

In high-altitude and high-latitude terrestrial ecosystems, climate changes exceeding those projected under RCP2.6 will lead to major changes in species distributions and ecosystem function, especially in the second half of the 21st century.