A landfill site, where waste is buried People have made many changes to the world they live in—and some of these have had harmful consequences. As the world population increases, there is need for bigger cities, new towns and farmland. Land has to be cleared, destroying the habitats of animals and plants. Loss of habitat, pollution and hunting have driven some animals to extinction, while others are endangered. Industrialization, when not regulated, is a major threat to the environment. Factories discharge harmful chemicals into rivers and seas, while greenhouse gases are released into the air by factories and vehicles.
Areas of land and sea at risk: huge areas of rainforest have been cleared, many coastal waters have been polluted, and the desert...Read More >>Areas of land and sea at risk: huge areas of rainforest have been cleared, many coastal waters have been polluted, and the desert spreads yearly.
The retreat of Pedersen Glacier in Alaska, pictured in summer 1917 (upper) and summer 2005 (lower).
Carbon dioxide, methane and chlorofluorocarbons (CFCs) are all greenhouse gases. In the right amounts, greenhouse gases in the atmosphere trap heat from the Sun so the Earth is not too hot or too cold. But if greenhouse gases build up, too much heat is trapped and the Earth becomes warmer. This change in climate, known as global warming, will have disastrous effects if current trends continue. The ice in the polar regions will melt, raising sea levels and causing severe flooding in low-lying areas. Changes in the climatic pattern worldwide are already leading to more violent storms, flooding and long droughts.
The largest ocean oil spill ever began on 20th April 2010 when the Deepwater Horizon oil rig off the coast of Louisiana, USA, exploded. The explosion killed 11 workers and the oil spill is thought to have killed over 8000 fish, turtles, marine mammals and seabirds.
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