The importance of the environmental services provided by ecosystems was evident in Costanza (1997). The estimations carried out indicate that the set of services analyzed for the entire planet was approaching an annual average value of 33 trillion US $ / year, considering that the estimation is skewed by the uncertainty of the methods used and by the absence in the analysis of some biomes and services.
If we compare this figure with the GDP of the entire planet at the time (18 trillion US $ / year), we can get an idea of what the ecological systems means in the economy. In the US alone, Pimentel (1997) estimated that the annual economic and environmental benefits of biodiversity were about 319 billion [$109] a year, and its total contribution to the planet was about 2928 billion [$109] a year, about 11% of the global economy.
A study conducted by an international team of scientists and economists, coordinated by the University of Cambridge and the Royal Society for Protection of Birds (RSPB), estimates that each year humanity has to provide about 250 billion additional dollars because the loss of the services that nature gives us for free. Also, it concludes that with less than $50 billion a year we could protect ecosystem services, and we are generating $5 trillion a year. This means that less than 1/16 of the world’s military spending budget could effectively protect the nature of the planet (Balmford et al., 2002).
However, while some of these goods and services are identified locally, and its benefits are easily quantifiable in terms of market (*), such as tourism associated with protected areas, many others are not valued under classical economics, and therefore may have little impact in policy decisions that affect them (Costanza et al., 1997). This leads to rapid degradation and depletion (Daily et al., 2000), as we are seeing today.
For these reasons, even from an purely utilitarian point of view, it is necessary to properly assess the ecological systems’ contribution to the economy through goods and services, with the aim of decapitalizing a society, ours, which depends on this authentic natural capital (*) for its maintenance (Goodland and Daly, 1996).