Abstract

In the last few decades we have become aware of the ecological problem, a problem of unprecedented scale and urgency. It consists of the danger that within our or the succeeding generation all life on earth, including the human species, will become extinct. This possibility rests on the one hand on the conspicuous changes in the global environment that are being effeted by human activity and, on the other, on a new physical theory of nonequilibrium thermodynamics. According to this discipline, complex dynamic systems like the earth's biosphere are extremely unstable. When internal or external fluctuations exceed a certain threshold, such systems collapse into a state of chaos, the outcome of which is in principle unpredictable. The new systems that emerge from chaos are more complex, flexible, and efficient in utilizing free energy, but their components and structure cannot be foreseen. By applying this theory to our biosphere we can infer that if the man-caused disturbances in it exceed a certain level, the biosphere will break down and, eventually, a radically different environment will form. Such catastrophes have already occurred in the course of evolution, wiping out chains of interdependent species and restructuring the biosphere. As two of our authors—V. I. Kurashov and V. I. Danilov-Danil'ian—point out, the fact that we cannot determine our biosphere's threshold and predict at what point the biosphere will descend into chaos is no comfort; on the contrary, it makes our situation all the more dangerous. It is clear that we must immediately drastically reduce our impact on the natural environment. How to do so is not at all clear.