Recent years have seen a surprising ball of the Earth’s elements. A procession of fires, floods and droughts makes one involuntarily think about the stability of climate on our planet. Scientists do their best to find the solution to this problem. Fellow scientists from laboratory of surface waters of the Institute of Water Problems (Russian academy of Sciences) have developed a model of Earth’s global climate – the model considers such parameters as temperatures of atmosphere’s bottom layer, amount of water absorbed by soil, and river discharge to the World Ocean. The crucial difference of said model from any other is consideration of our planet’s water balance. Calculations of Russian scientists predict alternation of global warming and cooling periods, caused by humidity variations.

Our planet has following characteristic: water has the highest heat capacity and solar energy absorbing ability among all natural substances of the Earth. The more moisture soil contains, the more heat it can hold. Soil moisturizing leads to growth of annual average atmospheric temperature, and global warming, in its turn, increases evaporation from river and ocean surface. Water vapor returns to the Earth as precipitation and makes soil more humid. Calculations have showed that global climate warming amounting to 1 degree increases average precipitation up to 1.6-2.6 per cent (2-3 cm per year). This is the way temperature growth promotes humidity increase, and humidity leads to further warming. The climate turns mild and becomes nearly the same everywhere on our planet. Fortunately, the Earth cannot be heated more, because soil is able to absorb only limited amount of water. Excessive water flows to rivers, soil dries out and cools down, thus Earth’s atmosphere cools down too, and evaporation slows down. The planet welcomes a cold and dry period – climate of polar regions and equator shows essential differences. However, since precipitation lowered significantly, dry soil starts absorbing water again – the process, which finally leads to another climate change and saves our home planet from being totally frozen. Then the described cycle repeats.

What is going on now on our planet? Studies of main climatic patterns showed that recent 10-15 years were the most warm and humid for the whole millennium. Soil gets quickly saturated with water, and its water bearing strata approach ground surface. Evaporation from World Ocean’s surface showed 40% increase, the same as atmospheric precipitation over continents. Most intensive rains were detected in North America, Russia, Europe and Australia. Mountain glaciers in Central Europe and Tropical Africa, Iceland, and Asia are shrinking very fast; sea ice of the Arctic basin and shelf glaciers of Antarctica also show rapid decrease of their areas. Rivers of European Russia are annually covered with ice 15-20 days less than one hundred years ago, and Siberian rivers – Kama, Belaya Ob’ and Irtysh – 9-14 days less. Spring comes earlier to the Northern Hemisphere. Thus, the “heating threat” of Earth’s global warming is real, however scientists tend to think that it is caused by natural reasons, not by burning natural fuels. Hence, lowering anthropogenic emissions of carbon dioxide, which is now the slogan of modern science, won't cause significant decrease of global air temperatures.

Sources:
    http://www.rfbr.ru
    http://www.dombayinfo.ru
    http://www.bio.vsu.ru/

Kizilova Anna