Global warming is a process of a long-term increase in annual average temperature of the Earth's atmosphere and oceans. The average temperature went up 0,7°C in comparison with the time at the beginning of the industrial revolution. (1850s). Anthropogenic factors, primarily greenhouse gas emissions such as CO2 and CO4, are the number one cause of global warming.

According to climate models average temperature of the ground surface will rise from 1,1°C to 6,4°C in 21st century. In some regions, temperature may go down a little. Acoording to many forecasts, at the beginning temperature will drop by a degree in Europe because of the Gulf stream slowing but later on will increasing rapidly. Global warming and sea-level rise are expected to grow over thousands of years, even in case of  greenhouse gas level stabilisation.

The growth of sea level and global warming will result in changing of amount and distribution of precipitation.  As a consequence, natural disaster such as  floods, droughts, hurricanes and other may become more frequent, crop harvest will decline and many species will go extinct.

Climate systems are changing under the influence of both natural internal processes and external effects. Greenhouse effect is one of the main cause of changing among external impact.

Greenhouse effect is a process whereby absorbtion and emitting of infrared radiation by atmospheric gases cause the warming of earth's surface and atmosphere.
Pollution sources are animal husbandry, use of fertilisers, coal combustion, car emissions, factories chimneys and other anthropogenic emissions. Landscape change such as deforestation above all is also the cause of greenhouse effect.

Scientists forecast the continuation of global warming, increasing of greenhouse gas emissions, growth of average temperature, sea-level rise.

The most probable changing weather patterns are as follows :

1. More heavy precipitation
2. Higher maximum temperatures, expansion of hot summer days and decline of cold winter days in almost all regions of the world, heat waves will become more frequent in the majority of inland areas.
3. Decrease in a range of temperatures 听起来自然吗？