Peter May profiles different frameworks for evaluating the sustainability of terrestrial ecosystems. One such framework is the Pressure-State-Response Framework (PSR), which has to do with the pressures that are brought to bear by human activities through economic activities such as energy use, transportation, industrial activity, agriculture, etc. The framework evaluates how those pressures affect state variables and the state of the environment, how this affects productivity and resource management, and the decisions states make in response. The Cost of Policy Inaction Valuation Process is another framework, a process of valuing the costs that are associated with not taking the right decisions at the right time in comparison to a baseline. It demonstrates how biodiversity loss can have a significant effect on GDP loss.