Nature's services is an umbrella term for the ways in which nature benefits humans, particularly those benefits that can be measured in economic terms. Robert Costanza and other theorists of natural capital conducted extensive economic analysis of nature's services to humanity in the 1990s. The economic contribution of seventeen of these was found to be approximately US$33 trillion per year, greater than the activities in the inter-human economy, which totaled about US$25 trillion. This was based on estimated costs of replacing the services nature provides, with equivalent services using methods wholly based on human infrastructure.
This study has been widely cited in natural capital, value of Earth and value of life debates. It is a cornerstone of human development theory and Natural Capitalism. It has also had broad influence on theories of service economy, which redefine commodity markets and brand name product sales strictly as services: for example, governments providing means of protection of the natural capital which automatically provides such services as:
Worldwatch Institute, World Resources Institute, Rocky Mountain Institute, Greenpeace, and various United Nations agencies, along with a few governments (including the United Kingdom and Canada) are actively expanding the analysis, with an eye to producing UN standards for valuating natural capital. This is anticipated to have a major effect on money supply debates, as the creation of money by banks for purposes of funding ecosystem depletion has become a major global governance issue, of importance equivalent to land reform, developing nation debt and terrorism. In combination, these are thought by some theorists, including Thomas Homer-Dixon, to be closely related to ecological depletion and heightened competition for scarce natural resources. If the nature's services analysis is valid, then humans also compete to protect the natural capital which in turn provides them services they cannot pay for in a cash economy. Funding its depletion thus creates a vicious cycle.
However, this debate appears to have had little influence on government policy or on WTO, IMF or G8 economic and trade policy. The anti-globalization movement, ecology movement, peace movement, and conservation movement, and their political ally the Green movement are increasingly vocal about the need to reflect the value of these services directly in real policy. Such an approach would, for example, mean not funding such projects as the Three Gorges Dam which directly deplete and disrupt ecoregions on a huge scale. This debate precedes economic analysis of the services, which was in part motivated by the observation that human instinct and economic analysis very often yielded quite different impressions of the value of such ecosystems.
One criticism of this analysis is that it is largely conducted by those who have some association with Gaia philosophy and human development theory and one or more political movements seen to have an ideological bias in favor of a higher valuation for nature's services than would be implied by a more neutral point of view. Accordingly, many of the debates now focus on metrics and indicators on which both advocates and detractors of monetary reform can agree. These are in general indistinguishable from debates about measuring well-being to determine what constitutes real economic development, that is, the amount of money required to live the same way, and other debates regarding the social welfare function and what constitutes wealth.