Natural resources are a major foundation of economic activity and human welfare. Their stocks are part of the natural capital and they provide raw materials, energy carriers, water, air, land and soil, and support the provision of environmental and social services that are necessary to develop man-made, human and social capital (see box next page). The extraction and consumption of resources affects the quality of life and well-being of both current and future generations. This includes oil and gas extraction, mining, fishing and forestry. Natural resources differ in their physical characteristics, abundance and value to different countries or regions. Their efficient management and sustainable use are key to economic growth and environmental quality. The aim is to optimise the net benefits from resource use within the context of economic development, by: .. Ensuring adequate supplies of renewable and non-renewable resources to support economic activities and economic growth. .. Managing the environmental impacts associated with the extraction and processing of natural resources, so as to minimise adverse effects on environmental quality and human health. .. Preventing natural resource degradation and depletion. .. Maintaining non-commercial environmental services. Progress can be monitored by looking at stocks of environmental assets, along with flows of environmental services, and by using indicators that reflect the extent to which the asset base is being maintained in terms of quantity, quality or value. The main issues of importance to green growth include: .. The availability and quality of renewable natural resource stocks including freshwater, forest, fish. .. The availability and accessibility of non-renewable natural resources stocks in particular mineral resources, including metals, industrial minerals and fossil energy carriers. .. The biological diversity and ecosystems including species and habitat diversity, and the productivity of land and soil resources.