Loss of Biodiversity

The loss of biodiversity is not a sudden event but a process that has been accelerating sharply in recent decades. The root cause is simple: human population growth has pushed up the consumption of natural resources, and that pressure has translated directly into the destruction of species and their habitats across the world.

The imbalance is stark. Tropical regions cover only about one-fourth of the world's total land area, yet they hold roughly three-fourths of the world's human population. To feed and support such dense populations, over-exploitation of resources and deforestation have become rampant. The tragedy is that these tropical rain forests contain about 50 per cent of all species on Earth. So when their natural habitats are destroyed, the damage is not local — it is disastrous for the entire biosphere, because the species lost there are irreplaceable.

Natural calamities also take their toll. Earthquakes, floods, volcanic eruptions, forest fires and droughts all damage the flora and fauna of affected regions, altering the biodiversity of those areas. But human activity adds another layer of harm. Pesticides and other pollutants — such as hydrocarbons and toxic heavy metals — destroy the weak and sensitive species that cannot tolerate such contamination.

A particularly damaging human intervention is the introduction of exotic species. These are species that are not natural inhabitants of a local habitat but are brought into the system from outside. There are many documented examples where a natural biotic community suffered extensive damage simply because an exotic species was introduced. The newcomers often outcompete, prey on, or displace the native organisms that had no evolutionary defence against them.

Hunting has been equally destructive. During the last few decades, animals like tigers, elephants, rhinoceros, crocodiles, minks and birds were hunted mercilessly by poachers for their horn, tusks, hides and other body parts. This relentless killing pushed certain types of organisms into the endangered category. …