Specialists know that at global level, the American environmentalist and scientist, Lester Brown, the pioneer of the rational environmental development, launched in 2001, the theory of the Eco-Economy, where he emphasizes the importance of the ecology and of the environmental protection, in the support of the sustainable development of humankind, a warning signal for the limited Earth resources. “Ecological and economical deficits shape to us not only the future, but even our present…”, declared Lester Brown in October 2010. 40 years ago, the American scientist of Romanian origin Nicholas Georgescu Roegen, launched the concept of Bio-Economy, which brings into discussions the role of humankind in the anthropic ecosystems, with the necessity to statistical demonstration of the negative energetic balance in the raw materials consumption and the lack of perspectives for future generations. Georgescu Roegen’s theory, in its concepts of Bio-Economy has humanistic attitudes which sent to an indirect social focus, the scientist considered that: “To enjoy life is the real purpose of the economic activity”. Taking into account that there exists a scientific contradiction between the 2nd principle of thermodynamics and the entropy law, versus the excessive use and the loss of the energetic resources, there is a warning on the necessity to balance the economic development, in order to have a global political economy which will respect the principles of biology.
 Lester Brown, (2001)- Eco-Economy: Building an Economy for the Earth, Earth Policy Institute, Washington
 Lester Brown, (2011)- “ Lumea pe marginea prapastiei. Cum să prevenim colapsul ecologic si economic”, Bucuresti, Editura Tehnica,
 Roegen Georgescu, N., (1971)- The Entropy Law and the Economic Process, Mass.: HarvardUniversity Press, Cambridge