Pollution of sea, rivers

Acid Rain

5. The amount of water in the world is limited. Water covers about two-thirds of the Earth's surface. But most is too salty for use. Water crisis is one of the most worrying problems for the new millennium. Today, one person in five across the world has no access to safe drinking water.

4. In the last 50 years we have lost 300,000 species. One of four mammal species and one in eight bird species face a high risk of extinction in the near future.

Global Warming

7. The global warming induced by greenhouse gases (largely by burning fuels) leads to the climate change. The area covered by sea ice is decreasing. The ice at the North and South Pole can melt causing serious floods in many parts of the world and turning into deserts others. Some scientists think that there is a definite link between the global warming and the hurricanes, the number of which has considerably increased recently.

An Increasing Human Population