Who Will Protect the Web of Life?/The Intricate Web of Life

Conclusion of Vanishing Variety

* Overexploitation. This has led several species to extinction. A classic case is that of a passenger pigeon.  In the early 19th century, it was the most abundant bird in North America. When it migrated-in flocks of a billion or more-it darkened the skies for days at a time. However, by the end of the 19th century, it had been hunted to the brink of extinction, and in September of 1914, in  a Cincinnati zoo, the last remaining passenger pigeon died.  Similarly, the American bison, or buffalo, of the Great Plains was nearly hunted  out of existence.  

* Human population growth.  The human family in the mid-19th century had  a population of one billion. One and a half centuries and five billion people later, humans are beginning to wonder whether they are in danger of exceeding the limits of their resources. Each year, as the human population continues to grow, species are becoming extinct at an alarming rate.

* Threat of global warming.  According to the Intergovernmental Panel on Climate Change, it is possible  that temperatures could rise by as much as 6.3 degrees Fahrenheit within this century. This may be too fast a jump for some species to survive. According to researchers, it appears that a contributing cause of the death of coral reefs  (anchors of much of marine biodiversity) is warming water. 

Scientists say that a three-foot rise in sea levels could eliminate a large portion of the world's coastal wetlands, the home of abundant biodiversity.  It is believed   by some that global warming may be affecting the Greenland and Antarctic ice sheets. If these were to melt, environmental catastrophe could follow. 

Next time: Who Will Protect the Web of Life?/The Intricate Web of Life - An Epidemic of Extinctions

From the Awake! magazine