There are many factors for the rise and fall of nations. One of them is change of environment. When historians and scientists turn their attention to the downfall of a nation, they apply Malthus’ theory, according to which the population increases geometrically while food produces mathematically.
This uneven development creates a gap between population and food. When the supply of food is not sufficient for the population, it results in famine and droughts. Consequently, a society loses its order, tradition and institution.
The other important factor to which experts point out is the cutting of trees in order to prepare land for cultivation as well as to use wood for fuel. This causes the desertification of soil and change of environment. Under these circumstances, people migrate from their habitat to other places in search of food and security of life. Experts are of the opinion that humans are responsible for destroying their environments, and then paying a heavy price for that.
Experts have also pointed out that the decline of the Harappan Civilization – especially the downfall of Mohenjodaro – was the result of a change in environment, when forests are cleared first for use of agriculture and then their wood is consumed for industrial production. This makes the land barren. When state administrations fail to remove garbage from cities, a number of different epidemics arise. As a result people, leave such cities for safer places.
There are plenty of examples in the history, which show how civilisations and cities are destroyed and depopulated because of the degradation of the environment. When historians and archeologists studied some of the Polynesian Islands, they were surprised to see their destruction and barrenness. Joshua MacFadyen, in his book titled ‘Time and Place: an environmental History’, records the sad story of an island. When people reached this island, they were amazed to see giant statues standing in the ground. The island was barren; there was no population, neither trees nor animals, nor birds nor any living soul. It was an enigma for as to how these big statues were brought there.
This mystery unfolded when archaeologists excavated the site and found remains of a lost civilisation. On the basis of evidence, archaeologists and historians reconstructed the history of the island. It was discovered that in its earlier period, when the island was populated by fewer people, food was plenty because of thick forests and a large number of animals and birds which provided them a healthy environment. However, with the increase in population, they cleared forests for agricultural land and used timber and wood to build houses and boats etc.
Gradually forests disappeared, and with them animals and birds as well. Wood was not available even to build boats. This forced people to stay on island. Further evidence showed that when there was scarcity of food, groups of people fought each other. In the end, as a result of hunger, there was evidence of cannibalism. Finally, the inhabitants of the island starved to death.
Another example is that of the Maya Civilization. Experts also point out its downfall because of a change in the environment. The population of its cities had the opportunity to migrate to other parts of the country where they found food and shelter.
Experts say that the ruling classes can be blamed for what happened to the environment. The elite did not care to put a stop to deforestation nor did they manage the irrigation system to produce food for the population. Civilizations disappeared because of the recklessness of the people.
History warns us to learn a lesson from those civilisations, which had disappeared as a result of violated environments. In the case of Pakistan, we are losing forests because of the timber mafia which is cutting trees and earning money by unfair means. In the cities, trees are being cut down in the name of development. Rich agricultural land is being converted into housing societies.
The indication of decline is evident by the pollution of rivers, degradation of soil and death of trees which has reduced the level of oxygen. As a result, all of society is plunged into crises – paving the way for its decline.