The planet Earth is only a tiny part of the universe, but it's the only place where human beings can live.Today, our planet is in serious danger. Acid rains, global warming, air and water pollution, overpopulation are the problems that threaten human life on Earth.Who is to blame for the disaster? The answer is simple: all of us. Our forests are disappearing because they are cut down or burnt. If this trend continues, one day we won't have enough oxygen to breathe.The seas are in danger. They are filled with poison: industrial and nuclear waste, chemical fertilisers and pesticides. The Mediterranean is already nearly dead; the North Sea is following. The Aral Sea is on the brink of extinction. If nothing is done about it, one day nothing will be able to live in the seas.Every ten minutes one kind of animal, plant or insect dies out for ever. If nothing is done about it, one million species that are alive today may soon become extinct.Air pollution is another serious problem. In Cairo just breathing the air is dangerous — equivalent to smoking two packs of cigarettes a day. The same holds true for many Russian cities. Factories emit tons of harmful chemicals. These emissions have disastrous consequences for our planet. They are the main reason for the greenhouse effect and acid rains. An even greater threat are nuclear power stations. We all know how tragic the consequences of the Chernobyl disaster are.Fortunately, it's not too late to solve these problems. We have the time, the money and even the technology to make our planet a better, cleaner and safer place. We can plant trees and create parks for endangered species. We can recycle litter. We can support green parties and put pressure on those in power. Together we can save the planet and all of us with it.