Life on Earth—The Importance of Biodiversity
What is Biodiversity and Why Is It Threatened? April 20, 2009—Biodiversity is the variety of life on Earth. This includes all plants, animals and their habitats. As you can imagine, the Earth’s biodiversity is mind-bogglingly vast. According to the USA’s National Science Foundation (nsf.gov), 1.75 million species of organisms have been discovered and described, but scientists estimate that tens of millions are yet to be discovered. Unfortunately, many plant and animal species on Earth are facing severe threats to their survival and are disappearing at alarming rates. While extinction is a natural process (generally, a species will last for an average of 2–10 million years), species and ecosystems today are threatened with destruction at a rate rarely seen in history. This is mainly a result of human actions. The five biggest threats to biodiversity are: Invasive alien species (IAS). Invasive alien species are those which are not native to an area. They can arrive there via trade, transport, travel or tourism, which have all increased hugely in recent years because of globalization. These species are harmful to native biodiversity in a number of ways, for example, as competitors, predators, parasites, or by spreading disease. IAS may also cause economic or environmental damage, or adversely affect human health. They are one of the greatest threats to biodiversity. Climate change. Climate change is predicted to play a major role in biodiversity loss. Incidents such as fires, floods and insect plagues are expected to become more frequent. Marine life, too will be by factors including rises in sea temperatures and increased acid levels in oceans, as the concentration of dissolved atmospheric carbon dioxide grows. Climate change will also greatly impact polar ecosystems, with effects such as thawing frost, decreased snow cover and losses from ice sheets.
youthink . worldba n k . org/is s u e s
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