Also discussed here: Cities change temperatures for thousands of miles(UCAR ATMOS News, Jan. 27, 2013) And here: City heat affects temperatures 1,000 miles away(The Times of India, Jan. 28, 2013) Today we review global climate modeling research that examined the contribution of the waste heat produced by buildings and vehicle emissions in very large cities. Although this heat is small compared to the warming from greenhouse gasses in the atmosphere for the entire world, the model simulations reveal large changes in the regional circulation near these cities which may intensify local weather events such as droughts or extreme storms.
Key Quotes:
"The burning of fossil fuel not only emits greenhouse gases but also directly affects temperatures because of heat that escapes from sources like buildings and cars..The extra "waste heat" generated from buildings, cars, and other sources in major Northern Hemisphere urban areas causes winter warming across large areas of northern North American and northern Asia”
“At the same time, the changes to atmospheric circulation caused by the waste heat cool areas of Europe by as much as 1 degree C (1.8 degrees F), with much of the temperature decrease occurring in the fall..Although much of this waste heat is concentrated in large cities, it can change atmospheric patterns in a way that raises or lowers temperatures across considerable distances,"
"The world's most populated and energy-intensive metropolitan areas are along the east and west coasts of the North American and Eurasian continents, underneath the most prominent atmospheric circulation troughs and ridges,"
“The world’s total energy consumption in 2006 was equivalent to a constant-use rate of 16 terawatts (1 terawatt, or TW, equals 1 trillion watts). Of that, an average rate of 6.7 TW was consumed in 86 metropolitan areas in the Northern Hemisphere.”
“ a doubling of CO2 can cause regional surface temperature changes of as much as 6 K, whereas land-cover changes due to deforestation .. can cause up to 2 K regional surface temperature change. In response to anthropogenic heating resulting from energy consumption, high-latitude regions of Eurasia can be warmed by as much as 1 K, and the northeastern US and the Canadian Prairies and Northwestern Territories can be warmed by up to 0.6 K"
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