The effect of the city's thermal islands is basically not a new phenomenon (today the largest cities have a temperature difference of around 10 ° C, smaller cities are 5 ° C or less), but the rapidly growing area of human settlements is rapidly gaining momentum. Looking at the height of a bird's flight, it is clear why the metropolis is creating an artificial reef in the countryside or an island made up of concrete, asphalt roads, paving of pavements and metal roofs of halls of shopping centers and production halls at their edges. All these materials, which dominate the surface of cities, however, serve as thermal batteries. They absorb the incident light and heat, and, in the form of heat, they blaze it back to their surroundings. On a hot, sunny day, it is not so obvious (as is heat), but it is worse at night, when the temperature of the hot city can be up to ten degrees higher than in suburban surroundings.
Thermal islands originate and affect us as a resultant combination of several factors that enhance climate change. "But virtually every hard-won victory in the field of global climate change can be easily eradicated by the uncontrolled effect of thermal islands," says author Richard Tol, professor of economics at Sussex University. Winning the match on two-step boundaries and not raising the average global temperature or reducing carbon dioxide emissions will not be our own concern until we live in overheated cities. In other words, if we focus only on the atmosphere polluting the chimneys of factories and the smoke of the colliding column of cars, we will not live better anyway.
The expected future increase in the temperature of the cities inhabited by the majority of the human population may have a number of unpleasant environmental, health and economic impacts. And as it turns out, if we redo the negative impacts of the climate on money, we will rather get the interest of the wider public and possible solutions. Tol and his team (made up of economists from Great Britain, Mexico, the USA and the Netherlands) set their predictions about the bleak future in the heat of 1692 cities in the world. Its results suggest that overheated cities will consume even more energy (such as air conditioning), paradoxically increasing the energy burden and thus supporting climate change. Losses resulting from higher energy consumption may average up to 10.9 percent of GDP in 2050.
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Overheated cities are hungry for electricity, suffer from lack of water, can not sleep in them. They are tired and unhappy people who are unproductive and often ill. "In fact, if we add to the balance of possible economic losses resulting from global climate change so far, we will add the effect of the thermal islands of the cities, we will increase the resulting estimates by 2.6 times," says Tol. The good news from Sussex is that the city itself can take a number of adaptation measures to interrupt this unpleasant effect and not have to wait for any global movement. "Practically the most effective are the steps at the local level," economists say . "From pavements that reflect more light and less heat, through the installation of green roofs and the planting of trees and plants in the streets."
"What's interesting? That these adaptation measures may not be massive and may not overload urban infrastructure, " adds Tol. "For example, it is enough to move 20% of the surface of the city to an adaptation model (said green roofs and white walkways), resulting in an average decrease in the city's temperature by 0.8 ° C. This adaptation is not free, but their contribution saves the city 12 times more. " Furthermore, on the basis of its data, it also points out that we have dramatically underestimated the impact of local measures that can reduce the impacts of climate change. "We can achieve the greatest benefits in the fight against climate change, both at global and local levels. Or, of course, their combination. " Still, it is mainly a local adaptation solution: " If global efforts fail for some reason, these local changes will still have a visible impact. "
Author: Radomír Dohnal
Source: Ekolist.cz
