Towards a Threat Assessment Framework for Ecosystem Services.

How can we tell if the ecosystem services upon which we rely are at risk of being lost, potentially permanently? Ecosystem services underpin human well-being, but we lack a consistent approach for categorizing the extent to which they are threatened. We present an assessment framework for assessing the degree to which the adequate and sustainable provision of a given ecosystem service is threatened. Our framework combines information on the states and trends of both ecosystem service supply and demand, with reference to two critical thresholds: demand exceeding supply and ecosystem service 'extinction'. This framework can provide a basis for global, national, and regional assessments of threat to ecosystem services, and accompany existing assessments of threat to species and ecosystems.