Environment performs 4 vital functions and is able to perform these functions without any interruption as long as demand of the functions is within its "Carrying capacity". What do you understand by the term "Carrying capacity"?

Resource extraction is less than the rate of regeneration of the resource

The environment is able to perform the 4 vital functions without any interruption as long as the demand on these functions is within its carrying capacity. This implies that the resource extraction is not above the rate of regeneration of the resource and the wastes generated are within the assimilating capacity of the environment. If this is not so, the environment fails to perform its most important function of life sustenance.