The environment means surroundings in which people, animals and plants develop and exist. More simplified it’s the world in which we live. The science that studies the relationship between different life forms in nature is ecology. Today the most serious ecological problems are: the pollution of the air, water and soil, the destruction of ecosystems and its balance, the disappearance of species of animals and plants, the weather changes, acid rains, the warming up of the earth surface, the destruction of tropical rainforests and breaking of the ozone layer. These damages are caused by the man himself and his technical progress.

Global warming and greenhouse effect
Scientists say the temperature of the earth could rise by 3°C over the next 50 years. This may cause draught in some parts of the world and floods in others, as ice at the North and South Poles begins to melt and sea levels rise. This is caused by the greenhouse effect. Normally, heat from the sun warms the earth and then escapes back into space but carbon dioxide and other gases in the atmosphere trap the sun’s heat and this is slowly making the earth warmer. And where does the CO2 come from? Well, people and animals breathe in oxygen and breathe out CO2. Trees take CO2 from the air and produce oxygen. But we produce CO2 also when we burn coal, oil, petrol, gas or wood. In the last few years people have burned huge areas of rainforests. This means that there are fewer trees and consequently more carbon dioxide. So another problem is:
Deforestation
There are two reasons for destroying the world’s forests: land and wood. The land is needed for crops and wood is exported and used for buildings or made into furniture. Unfortunately, many rainforests grow on poor soils and when the trees are cut down, the soil is washed away by the rain or blown away by the wind soon, and the area may turn to desert. But many plants and animal species that live there could become extinct. All of us are to blame for this disaster. However, some people can’t sit passively. They join some organizations which try to save the nature in the world. World Wildlife Fund is one of these organizations, too. It protects endangered spaces, saves endangered species and informs about global threats. In the world there are many animals and plants we have to protect.