The human problem A changing earth system

In recent decades, humans have become a very important force in the earth system, demonstrating that emissions and land use change are the cause of many of our environmental issues. These emissions are responsible for the major global reorganizations of biogeochemical cycles. With humans as part of nature and the evolution of a man-made changed earth s system, we also have to accept that we are unable to remove the present system into a preindustrial or even prehuman state because this means disestablishing humans. The key question is which parameters of the 

The time scale of the adaptation and restoration of natural systems is much larger than the time scale of man-made stresses (or changes) to the climate system. We should not forget that nature cannot assess its own condition. In other words, the biosphere will accept all chemical and physical conditions, even worse (catastrophic) ones. Only humans possess the facility to evaluate the situation, accepting it or not, and coming to the conclusion of making it sustainable. Under the aspect of chemical evolution, this section briefly outlines the role of humans in forcing the climate system. Let us define a sustainable society as one that balances the environment, other life forms and human interactions over an indefinite time period. 

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