Intergovernmental Panel on Climate changes predicting active expansion of drylands as a result of global warming, it seems to be mistaken. According to a new study, it turned out that modern methods for assessing drought strength are incorrect. The situation is not so sad, as climatologists predict. 
Photo from open sources In order to assess the balance of precipitation and losses soil moisture – as a result of either direct evaporation or assimilation water plants followed by its evaporation through the leaves – the Palmer Aridity Index is applied. Usually in this the method uses only temperature and latitude terrain. According to hydrologist Justin Sheffield of Princeton University in the USA, the method gained great popularity in the first turn because of its simplicity. However, the simpler the technology, the Naturally, the results are rougher. Scientists have long known that Vapors are influenced by many other factors: speed wind, relative humidity, solar light that reaches the planet’s surface at various lengths waves. However, only recently Sheffield and colleagues managed to hold reconstruction of global data on these parameters until 1948 of the year. In their work, they used satellite data. Then scientists calculated the strength of the drought from 1948 to 2008. As a result it turned out that the drought rates were very high. For example, by the new methodology turned out that from 1980 to 2008 the area of districts, in which there was a strong lack of moisture, increased approximately 0.8% annually, which is seven times lower than the result obtained by based on temperature alone. These findings confirm yet another analysis of these same scientists, which revealed that for the most part drought It was noted only in the 1950s and 1960s, that is, it does not depend on global warming. Shameful colleagues began to defend themselves. By According to Pierce Forster of the English University of Leeds, in any case, droughts in Europe, Africa and China have become more strong in the second half of the 20th century, regardless of the method dryland estimates. The climatologist emphasized that drought is not is the only danger. Elevated temperature negatively affects crops and without it. Other According to her, although Sheffield and colleagues found an important flaw, this does not reduce the threat to the food industry due to climate change. The authors of the new work do not dispute last conclusion. Moreover, they said, the effect of global warming was offset by a number of factors, otherwise case, the drought would be even stronger. The thing is, from the 1960s on 1990s there was a slight decrease in the amount of solar radiation reaching the planet due to air pollution particles scattering light with a specific wavelength back. In addition, in the period under review, the wind speed at the Earth surface decreased, which also reduced evaporation.
Global warming
