Global Warming

The climate of the Earth is influenced with set of factors, including those on which the human has no an opportunity to influence, for example, astronomical and geological. However in last decades it is more and more spoken about influence of a human civilization on a climate.

Forecasts about change of a climate are done on the basis of mathematical models which use various sources of the information. In particular, it is data by satellites (approximately for last 20 years), statistics of world temperatures (similar measurements are constantly made since the middle of 19th century), and also Paleozoic-climatic data (those receive using archeological and geological researches, the analysis of an ancient ice - for example, the ice in Antarctica contains bubbles of air which analysis allows to define concentration of carbonic acid, methane ,gases and so forth a lot of millennia back) .

In the last decade the set of forecasts about destructive consequences of global warming is published. The basic conclusions are approximately those: increase in quantity and duration of droughts and forest fires, increase in number of powerful flooding and hurricanes; to epidemics, famine and so on

For example, the Intergovernmental Panel on Climate Change (unites 2.5 thousand scientists from the 130 countries) in 2007 has predicted, that if the world temperature will raise on 1.5-2.5 degrees on a scale of Celsius under threat of disappearance there will be 30 % of animals and plants. By 2050 more than 1 billion person will suffer from chronic shortage of potable water. By 2020 in hot parts of a planet the agricultural areas be cut by half.

The report published in 2007 by the United Nations program on the Environment, in particular approves, that in Antarctic and Greenland are stored 98-99 % of a surface fresh-water ice of a planet. If the ice cover of Greenland will thaw completely, the level of world ocean can rise on 7 meters. But even in case if the ice cap of Greenland will thaw on 20 %, and Antarctic’s - on 5 % it will lead to rising of a level of world ocean on 4-5 meters. This all can happen in the next century. Thawing of these glacial covers jointly with thawing of mountain glaciers and snow caps has already led to that the level of world ocean has risen on 20 cm for the period between 1870 and 2001. And the level of ocean rose annually on 3 millimeters during between the beginning 1990 and 2006.

Increase of a level of ocean on 1 meter will lead to that 145 million person will appear in area of overflowing and flooding. It can lead to disappearance of some countries, for example, Holland, Pakistan and Israel, to flooding of a greater part of Japan and some other island states. Such cities, as St.-Petersburg (Russia) and New York (USA) can disappear under water.

Global warming has many explanation. Main it is considered increase of concentration of “hotbed” gases, namely the gases promoting occurrence of “hotbed effect”- characteristic of an atmosphere to pass solar radiation ,but to hold terrestrial radiation and by that to promote accumulations of heat by the Earth. One of the basic hotbed gases is carbonic gas which achieve in an atmosphere as a result of process of combustion. There are also other factors: negative influence is submitted by way of cutting down of woods, extraction of minerals, etc.

National Research Council specifies, that noticeable influence on a climate is rendered by changes during use terrestrial goods . For example, it influences at quantity of an solar radiation absorbed and reflected by terrestrial surface. Besides there is also other effect. For example, one of ” hotbed gases ” is methane ,which two thirds of emissions are caused by activity of the human. Methane is produced during cultivation of rice, cultivation of large domestic animals, a coal mining and so forth As a result, nowadays concentration of methane in an atmosphere is record-breaking high, and the level of concentration stably raises since the last half of 20th century.

By estimations of the National Climatic Data Center, for last century the maintenance of carbonic gas in a world atmosphere has grown from 300 up to 380 parts on 1 million, and the average temperature of a terrestrial surface has grown approximately on 0.7 degrees on a scale of Celsius. Last decade of 20th century became the warmest during making of measurements of standard temperature (from the middle of 19th century). 1990th years were included into count as the warmest 15 years, six years of this decade were the “hottest” years of century. In turn, company Accu-Weather ,which is engaged in commercial use of meteorological data, approves, that in 20th century the average world temperature has risen on 0.45 degrees on a scale of Celsius.

Thus , the temperature most quickly raises in Arctic regions (Siberia, Alaska, Canada). By estimations of the international group of scientists (refers to Arctic Climate Impact Assessment), near to North Pole temperatures grew twice as much quickly, than, as a whole ,on a planet. It is supposed, that by 2040, or even earlier, the Arctic ocean can remain without an ice. In Northern hemisphere the spring (within temperature, not within calendar sense) appears on one week earlier, and winter - a week later, than on previously century.

In the world the quantity and the sizes of mountain glaciers and snows decreases. For example, according to magazine National Geographic, in territory of hilly state of Montana (USA) in 1910 were 150 glaciers totaled, and in 2007 remains only 27.