4-4Human Activities Can Cause the Premature Extinction of Species

Although extinction is a natural process, the scientific consensus is that humans have become a major force in the premature extinction of species. Human activities decrease the earth's biodiversity when they cause the premature extinction of species and destroy or degrade habitats needed for the development of new species.
雖說物種滅絕是一個自然過程，但人類活動減少地球的生物多樣性。
According biologists Stuart Pimm and Edward O.Wilson and the 2005 Millennium Ecosystem Assessment, extinction rates increased by 100-1,000 times the natural background extinction rare during the 20th century. As human population and resource consumption increase over the next 50-100 years,our ecological footprints are likely to expand. In addition, we are also expected to take over an even larger share of the earth's surface and net primary productivity that supports all consumers.
隨著人口和資源的消耗增加，我們也需要一個更大的初級生物網以支持所有"消費者"。

According to Wilson and Pimm, this plus climate change may cause the premature extinction of at least one-fourth of the earth’s current species by 2050 and up to half of those species could be gone or headed for early extinction by the end of this century. This could deplete and degrade the natural capital that supports all life and our economies. According to Wilson, if this massive loss of species continues unabated, the cost to humanity in wealth, environmental security, and quality of life, will be catastrophic. Wilson also says that if we make an “all-out effort to save the biologically richest parts of the world, the amount of loss can be cut at least by half.”

據威爾遜和皮姆物種繼續有增無減，對人類的費用財富，環境安全，和生活質量，將是災難性的。威爾遜還表示，如果我們作出了“全力拯救生物最豐富的地區，損失數額可減少至少一半。

It took millons of years after each of the earth's past mass extinctions for life to recover to the previous level of biodiversity.Thus, on our short time scale, such major losses cannot be recouped by formation of new species. To make matters worse, we are also destroying or degrading ecosystems such as tropical forests, coral reefs, and wetlands that are centers for future speciation. See the Guest Essay on this topic by Norman Myers at Thomson.

生物大滅絕後需要幾百萬年後才能恢復到以前生物多樣性的水平。