Where does the wind? Somebody will say the work is in the difference of temperatures: hot air rises, cold drops. In school textbooks and write.

What if the winds, commanding atmospheric circulation, are created above all by condensation? And this occurs mainly in tropical forests: the moisture evaporates, it seeps through the trees. Physics and foresters, defending this controversial idea, say that if we cut down forests, we lose the winds and rains, which they generate.

The physical process by itself is not disputed. Whenever water vapor condenses into drops, its volume is reduced, the pressure decreases. Formed emptiness fills the air and creates the wind.

Climatologists have always considered this effect is banal. In part this is related to the sharp criticism of the hypothesis, first proposed four years ago. "There is nothing mysterious, " says Isaac held from the U.S. National oceanic and atmospheric administration research. Is insignificant effect, it is considered in some models of the atmosphere".

But physicist Anastassia Makarieva from St. Petersburg University believes that created this effect pressure gradient still not received the proper theoretical attention. Her calculations suggest that condensation billion gallons of water over the giant forest gives a tangible effect.

According to Douglas Sheila from southern cross University (Australia), critics have yet to explain why they believe that Ms. Makarieva not right.

Judith Curry of the Technological Institute of Georgia (USA), author of the standard textbook on Thermodynamics of the atmosphere and oceans", explains: "the process, which they describe is physically correct. The main issue is its relative value compared with other processes. Perhaps this explains why climate models so bad at predicting rains and hurricanes".

No one doubts that forests recycle rain due to evaporation. But nobody thought to entrust this process is responsible for strengthening of the winds, which carry the damp sea air on the continents.

The consequences are enormous. "In the standard theory, if we do not consider forest precipitation over the continents usually decrease by 10-30%. In our theory, lost somewhere 90 and more percent", - emphasizes Mr. shale.

But it is not the bad news. If unaccounted forest transplant, says a new theory, then the winds which they generate, will bring rain even in the drylands. It is no coincidence that six thousand years ago, the Sahara was a flowering plain.

Prepared according to NewScientist.