Nowadays, more and more people have cognizance of that traditional GDP accounting easily exaggerates the economic benefit, which cannot account the cost of ecosystem degraded and environmental pollution due to economic growth. So Green accounting has been a hot topic in system of national economic accounts in recent years. At present, the green accounting had considered the ecological costs owning to traditional economic growth model in macro-scale. Whereas, from the costs accounting, we can’t got what ecological functions were affected by economic growth, so there is not enough information to support decision-making. On the sake of this, this article tries to introduce the ecosystem services to address this matter in local scale.
Ecosystem services （ESs）provided a monetary method to evaluate the ecosystem benefit for human and the technique related ESs can also be used to account the value of the green GDP. ESs is an invisible benefit for agricultural production, and these services have huge values for social economic system. Nevertheless, on traditional view, agriculture system can only provide foods output or other materials. Agroecosystem is a kind of artificial-ecosystem, it need inputted by not only natural resources, but also manpower. In this article, we regard that agroecosystem had double inputs (natural and artificial) and output (products and indirect output, e.g. ecosystem services). The services have great value for human society directly or indirectly. Based on these ideals, a formula was putted forward to account agricultural production in this article. That is:
Green GDP = traditional GDP + ecological GDP
Through the accounting for the value of production goods, production costs, ecological costs and the ESs in case of Ansai County (in Loess Hilly-gully region of China), the results showed that:
The traditional GDP of Ansai County in 2000 years is 189.72 million yuan RMB based on the traditional economic accounting. Under considered the ecological costs, the net value of agriculture outputs is 62.72 million yuan RMB merely, which is 33.06% of the traditional GDP. And, if we taken the ecosystem services as a kind of ‘outputs’ of the agriculture production system, then the total value of agriculture production system is 5104.91 million yuan RMB. Thus, we can make clean the deficiency of traditional GDP accounting, which had not account the ecological costs and ecosystem services. When taking the ecological costs and resources ‘ullage’ into account, the net output is merely 33.06% of the traditional GDP. In a other words, there are 66.94% of the agriculture outputs were supported by the services of the production system. So the ecosystem services conservation had a significant role in Ansai County economic, ecological and social development.
At last, Green GDP is involved with the accounting of natural resources. At present, for different kinds of ecosystem, there is not a convictive and consentaneous method to account the value of ecological degradation and ecosystem services. The index system must be conforming to scientific and operable character. In this article, we just took the first step to explore how to account the agriculture production system with ‘green’ method, further efforts are needed to take in next step.