Two new important developments in environmental and resource economics is presented—non convex dynamics of ecosystems and wealth as an indicator of sustainable development. Non convex dynamics imply existence of resilience, that is the robustness of systems to withstand exogenous perturbations. Resilience can be regarded as an insurance against flips of the system into different basins of stability. Sustainable development, according to the Bruntland report, is the provision of productive resources to future generations to make it possible for them to live as well as the present generation. Thus, the value of changes in productive assets is therefore an index of whether an economy is on a sustainable path or not. Resilience can be regarded as one such productive asset and the paper discusses how one can define the value of this asset.