Book excerpt: 2007 marked the 20th anniversary of the G.H.Brundtland Commission report that broke new ground by addressing the issue of sustainable development as a means of avoiding an ecological catastrophe. This led to a multitude of political declarations, documents and scientific articles while Agenda 21 – adopted in 1992 in Rio de Janeiro – has been accepted by the governments of more than 100 countries. Sadly, however, this has not prevented certain recent dangerous trends, nor have the wider public, journalists, business circles or politicians grasped the urgency of the problem. It is therefore important to make humanity understand its real place in the natural environment and the gravity of the ecological threat before us. The exclusive role of natural ecosystems is a key factor in the maintenance of the biospheric equilibrium. The current global crisis is largely caused by their dramatic decline by 43% in the past hundred years. Ignoring the immutable laws and limitations which determine the existence of all living things in the biosphere could lead humanity to an ecological catastrophe. This book presents the ecological, demographic, economic and socio-psychological manifestations of the global crisis and outlines the immutable laws and limitations which determine the existence of all living things in the biosphere.