Why Are Polar Bears Threatened

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Why are these polar bears threatened?

These polar bears are threatened because of global warming. They depend on the sea ice for their hunting grounds, and this ice is melting away. Plus bears have to make a longer and more hazardous journey to get to the remaining ice.

Other Causes of Extinction
In addition to habitat destruction, other human-caused problems are also threatening many species. These include issues associated with climate change, pollution, and over-population.

Global Warming
Another major cause of extinction is global warming. During the past century, the Earth's average temperature has risen by almost 1°C (about 1.3°F). You may not think that is significant, but to organisms that live in the wild and are constantly adapting to their environments, …show more content…

This can have many different harmful effects on all kinds of organisms. For example, the pesticide DDT nearly eliminated the peregrine falcon in some parts of the world. This pesticide caused falcons to lay eggs with thinner shells. As a result, fewer falcon eggs survived to hatching. Populations of peregrine falcons declined rapidly. DDT was then banned in the U.S. and peregrine falcon populations have …show more content…

The human population passed the 7 billion mark in October of 2011, and will pass 8 and 9 billion probably before the middle of the century. All these people will need resources such as places to live, food to eat, and water to drink, and they will use energy and create waste. Essentially, human population growth can effect all other causes of extinction. For example, more people on the Earth means more people contributing to global warming and pollution. More people also means more clearing of land for agriculture and development. Recall that development by humans often causes habitats to be destroyed. This destruction can force species to go extinct, or move somewhere

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