As an example of such changes, scientists cite two phenomenon – the increase in average annual temperatures in provincial areas of the United States by 1 degree at a distance of several thousand kilometers, and their decrease by 1 degree in Europe. 
Photo from open sources © RIA Novosti. Igor Mikhalev Big cities turned out to be giant stoves that could boost annual average temperatures of one degree Celsius in remote rural areas even a few thousand kilometers away them, which indicates an underestimation of the role of megacities in climate change, say climatologists in an article published in the journal Nature Climate Change. “We found that the lost heat generated large cities, able to warm the atmosphere in remote from them regions. This phenomenon arises due to changes in air mass circulation caused by surplus emissions heat in homes and other parts of cities, “said the head a group of scholars Guang Zhang from the University of California at San Diego (USA). Zhang and his colleagues came to this conclusion, appreciating the amount of heat energy emitted by large cities North America, Europe and China into the environment. As noted authors, global contribution of residual heat to change the climate itself is negligible – according to the most common estimates, they increase the average temperature on earth by only 0.01 degrees. Not less, the situation in reality is completely different, since the general climate models do not take into account that this heat is distributed not evenly, but concentrated in large urban agglomerations. By estimates of Zhang and his colleagues, half of the global “surplus” heat – about 6.7 terawatts of energy – was generated by large megacities occupying a relatively small part of land. Thanks to this, for every square meter of a typical metropolis accounted for 0.4 watts of residual heat. According to researchers, this is enough for the emergence of significant changes in the wind cycle in the cities themselves and on the big distance from them. As an example of such changes, scientists give two phenomena – the increase in average annual temperatures in U.S. provinces 1 degree over several thousand kilometers, and their decrease by 1 degree in Europe. According to Zhang and his colleagues, such a major change in meanings annual average temperatures should be considered when modeling how the Earth’s climate will change in the future.
US climate
