It has been stated that positive and negative feedback loops lie at the core of the systematic thinking about the future.
Positive feedback loop states that basic trend generates secondary effects that in result reinforce the basic trend.
For example, If we go for car pooling and more usage of public transport then this basic behavior leads to considerable personal savings (in terms of money spent on gasoline) and environmental savings which will further induce us to rely on public transport as well as look for other alternatives which will bring more monetary as well as environmental savings for us.
Another example on positive feedback loop would be the relationship between methane emission and climate change. Methane is one of the important green house gases and it creates green house effect which keeps the earth warmer and made the life possible on earth but increase in methane emission will raise the temperature further. This rise in temperature will in result lead to release of methane that is trapped in Polar Regions. Thus, this release will further increase the quantity of methane emitted into atmosphere leading to further rise in temperature and in this way this process will repeat itself.
Negative feedback loops states that basic trends generate secondary effects that in result limit the basic trend.
For example, In New Mexico, in order to revitalize a wildlife park, authorities decided that native deer species should be conserved and predators of these deer species should be eliminated or moved out. This act by authorities to restore the natural environment of Wildlife Park by conserving native deer population instead of positive outcome resulted in negative outcome. Unchecked growth of deer population has put unnecessary burden on the ecological capacity of park and resulted in degradation of environment and death of large number of deer. This reduction in deer population ascending to such an extent where environment has began to grow again.
Another example of negative feedback loop is the usage of chemical fertilizers. Initially, usage of chemical fertilizers leads to increased production and productivity. But this increased usage of chemical fertilizers over time reduce the crop bearing capacity of land and also pollute the surrounding water resources leading to spread of many deadly diseases such as cancer etc. This prompts the farm community to decrease the usage of chemical fertilizers or in some cases land becomes barren as well thus automatically puts a full stop to the usage of chemical fertilizers.
The growing concern towards the degradation of environment has led to two different yet contrasting perspectives. One group of scholars proffers that the apprehension about the plight of ecology is meretricious and the situation has been exaggerated. Societies in the past also have successfully confronted these environmental problems and there is no reason to expect that the same would not continue. The other group, however, believes that the current development is unsustainable as it had led to a situation of ecological collapse.
The second approach presents a strong case of pessimism that blames the growth of population and economic development for the current situation. Degradation of ecology has resulted in a situation where the carrying capacity of the planet has reached and regeneration capacity has surpassed. Global poverty has come down but the intensity has increased. The addition of another billion people in the population in a decade or so will only aggravate this situation.
Concept of Finite resource base is useful because it remind us of the fact that resources at our disposal are limited. We know that human wants are unlimited and therefore in face of limited resource base, there is scarcity and meaningful choices have to be made. Nature has limited capacity to bear the environmental damage as subjected by the human beings. If bearing capacity of the nature with regards to environmental damage exceeds beyond its limits then it will result in serious consequences and may wipe out human civilization altogether.
Examples of wipe out of many ancient civilizations like Mayan civilization have been recorded in the past as well and environmental damage was known to be at the core f such destruction.
Finite resource base also put up another question and that is of sustainable use of resources so that not only present generation be able to use the resources but resources should be conserved in the manner that future generations be able to have the adequate resources at their disposal as well.
Finite resources base also induce the society to look for ways to solve environmental problems because degrading environmental leads to destruction of natural resources and thus further diminish the already limited resources.