The relationship between population and consumption might not be a concern for most people. In fact, most of these people might only have a little knowledge of this relationship because they do not realize the importance of it. They might feel that population and consumption do not intervene with each other. However, their interpretation is not true, the connection between them is extremely important for the society to focus on. This is because of the rapid growing population over these decades. Since population begins with people and their key events of birth and death, so as long as they are still alive they will consume the world's energy which includes food and material. Thus, to achieve a good estimation of consumption, the IPAT identity may be used. With the current world population is more than six billion people and growing at a rate of 1.3 percent per year, means the population will require much more resources. Additional to this, it is projected by the year 2050 there will be 8.9 billion people living on this planet, therefore it is necessary for the world to slow down the growth of the population and find alternate resources on earth to satisfy humans' need.
             Furthermore, consumption rate have been increasing very rapidly from the 1950s to now. This rapid increase is not only due to the increase in population but because people are increasing their standard of living. This can been seen by comparing the population data and consumption data between 1950 and 1990s. From 1950 to the early 1990s world population have doubled (2.2 times), while consumption of food have almost tripled, energy more than quadrupled (4.4 times) and the economy quintupled (5.1 times). Thus, with technologies this increase in consumption will not stress the resources by a lot because the input per unit of consumption have actually decreased and of information substitutes for more material and energy inputs. But, at the same ...