Hot town, summer in the city: cities are warmer than the surrounding area. In the summer the main reason for this lies in the fact that the city has less water to evaporate than in the country. This is the conclusion of researchers after the analysis of urban climate data from 60 US cities. To avoid “urban heat Islands” and improving the city’s climate, more plants and more unsealed areas are therefore needed, write in the journal “Science Advances”.
Growing cities, rising temperatures
More than half of the world’s population now lives in cities. This proportion will continue to grow. The Team led by Dan Li of the Boston University (in Boston, Massachusetts, USA) writes in his study, it was known for a long time that cities are generally warmer than surrounding rural areas. This heat island effect could affect the air quality, energy consumption increase and the health effects of heat waves increase.
so Far, different causes of urban warming are discussed. This includes the storage of heat in rock and concrete, or waste heat from industry and dwellings. Li and his associates used a new model to be able to the influence of the various factors more accurately. Whether and how much heat Islands arise in a city of the day depends, therefore, mainly from the soil moisture and the Vegetation in the cities.
Berlin: BSR-infusion
On the simple formula of “more for urban Green, more urban Blue” – Blue is not for exterior paints or the like, but for water it brings Uwe Schlink, Helmholtz-centre for environmental research (UFZ) in Leipzig: Green and water areas can influence the climate in the city is positive. Because of the Transition from liquid water to water vapor consumes heat energy and provides evaporative cooling. Water evaporates not only from bodies of water, but also of plants and from the soil. In order to explore the influences in more detail, will be constructed this year at the UFZ, a green roof for the purposes of research, reported Schlink.
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In overheated cities, the authorities often resort to measures such as sprinkling water in streets, evaporates there and then quickly. You – in Berlin, in the meantime, as “BSR-infusion” known, however, regarding its effect are controversial.
Frankfurt: Green living room
Petra Fuchs from the German weather service in Offenbach, sees an increased awareness for the topic: “We’ve had several requests from cities for urban climate studies”. Especially larger cities have the resources and the ability to recommended to implement the measures. In cities with specific climate conditions, such as Stuttgart, with its valley location, is the need for the improvement of the city climate is particularly high. There is now a wide variety of projects that are tackling the Problem. As an example, Fuchs called the mobile green living in Frankfurt am Main – a portable planted wall with Seating.
The effect, that it is in cities warmer than the surrounding country, was discovered about 200 years ago by the British chemist and meteorologist Luke Howard (1772-1864). According to the assessment of Schlink and Fox’s efforts to be a good climate in the city will be before the Background of climate change in the future is even more important.
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heat in Berlin BSR-infusion fresh: Sauna or summer?
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As the most important reason why cities in the Winter tend to be warmer than the environment, heaters, and waste heat-energy processes, also, about the heating of internal combustion engines. (rif/Reuters)
