Natural and extensively used ecosystems regulate regional climate and water cycles, store carbon, and provide a range of other goods and services to human societies. Disruption of their functioning may have severe impacts on regional agriculture. Under the combined pressures of human land use and changing climate, ecosystem functioning is threatened if the rate of change exceeds natural adaptation potential. Ecosystem conserving management could concentrate on regions with a high risk of catastrophic change, if they were known. However, as ecosystems are complex systems and some processes determining system behavior are poorly understood, predictions of future ecosystem dynamics and composition are highly uncertain. The approach to estimating ecosystem integrity change under climate change is therefore derived from macroscopic system properties: vegetation structure, carbon storage potential and net primary production (NPP) as key ecosystem properties are simulated with the dynamic global vegetation model. The author assumes a higher need for adaptation and hence a higher probability of exceeding an ecosystem's adaptation potential.