Habitat can be destroyed directly by many human activities, most of which involve the clearing of land for other uses such as agriculture, mining, logging, hydroelectric dams and urbanization. Habitat can also be destroyed indirectly by human activities such as pollution, fragmentation, climate change and the introduction of invasive species. Although much habitat destruction can be attributed to human activity, it is not an exclusively man-made phemomenon. Habitat loss also occurs as a result of natural events such as floods, volcanic eruptions, earthquakes, and climate fluctuations.
Although habitat destruction primarily causes species extinctions, it can also open up new habitat that might provide an environment in which new species can evolve, thus demonstrating the resiliency of life on Earth. Sadly, humans are destroying natural habitats at a rate and on spatial scales that exceed what most species and communities can cope with.
Habitat destruction is fueled by a fast-growing human population. As population increases, humans use more land for agriculture and cities and towns spread out ever-widening areas. The effects of habitat destruction not only impact native species and communities, but they impact human populations as well. Degraded lands are frequently lost to erosion, desertification, and nutrient depletion. Natural disasters such as floods, droughts, outbreak of pests and water pollution take a toll on human populations.
Conservationists often seek to protect habitat in order to save species. For example, the Biodiversity Hotspot program organized by Conservation International protects fragile habitats around the world. Their aim is to protect areas around the globe that contain high concentrations of threatened of species.
Habitat destruction is not the only threat facing wildlife, but it is quite likely the greatest threat. If the depletion of natural habitat around the globe does not slow, mass extinctions are sure to follow.