...By itself, the hotbed effect is vital for humans, animals and plants. Without it the Earth would become a long icy wilderness - with an average temperature of -18 ° C. Another question - the amount of carbon dioxide in the Earth's atmosphere. All the last millennium, it remained relatively constant - evidenced by the samples taken in the eternal ice of Greenland. However, to date, the proportion of CO2 has increased significantly - today is already more than 380 ppm. Total half-century ago it was 315 ppm ...
The fact that the concentration of carbon dioxide in the atmosphere is growing rapidly, even the opponents do not deny the theory of the hotbed effect. They just do not agree with the fact that this led to a rise in average temperature on the planet. The main argument of sceptics is that: some increase in global temperature took place and in first half of XX-th century – before the mankind has started to throw out in atmosphere unknown until then quantities of carbonic gas. The reason for the then warming, in their view, fluctuations in the intensity of solar activity.
However, meteorologists have long taken into account natural changes in solar radiation. Computer models of a climate show: a rise in temperature primary factor – increase in volumes of carbonic gas in atmosphere.
Analysis of the huge number of local measurements of climatic parameters over the past 100 years, also spoke in favor of the connection between the amount of CO2 in the air and warming. Average temperature of our planet during this period increased by 0,8 ° C - up to 14,5 ° C.
For a long time, the heating effect is restrained. Industrial emissions contain not only CO2, but also large amounts of sulfate - sulfur compounds. Getting in the atmosphere, they are transformed into sulfate aerosol particles that reflect sunlight and thus prevent heat the earth's surface. Since the late 1970's Western industrialized countries have reduced emissions to the atmosphere of sulfur compounds, but in Asia, this figure has grown. Therefore, until the end of the last millennium - the average concentration of sulfate remained more or less constant - while the amount of CO2 in the air, an annual increase of 1,5 ppm.
Pace of these changes is that the hotbed effect threatens to spiral out of control. If during the twentieth century, global temperatures have risen by 0,8 ° C, some of them 0,6 ° C occurred in the past 30 years.
Already there is no doubt that the earth is warming, and we are dealing with a stable trend. By the end of the XXI century the global average temperature will increase by 2-4,5 ° C (exactly how much depends on the emissions of CO2). This is the forecast of IPCC - the UN International Commission on climate.
The increase in global temperature is most noticeable in the areas covered by eternal ice. Compared with the beginning of the twentieth century alpine alpine glaciers declined by almost half. In Greenland, continental ice is melting three times faster than even at the turn of the last and this century: from April of 2002, about 240 cubic kilometers of ice per year forever transformed into the water, steadily raising the level of the oceans.
Decreases and the zone of permafrost in Siberia, Canada and Alaska. It was there lie huge reservoirs of methane. This gas deep beneath the earth formed a connection to the water - methanehydrates, methane ice. Further warming threatens to melt and release into the atmosphere incredible amount of methane. As the hotbed gas methane, by the way, is 20 times more effective than CO2…