Heat Wave

Researchers already know that humans are changing the climate by emitting greenhouse gases and transforming natural landscapes into cities. Now a new study suggests that the heat released from massive energy use in urban areas also contributes to warming of faraway northern regions.

In crowded cities, “a tremendous amount of energy is consumed each day,” the authors write in Nature Climate Change. They cite the example of Tokyo, which uses as much as 1,590 watts per square meter on winter mornings. Heat generated by energy use might be enough to affect atmospheric circulation and change temperatures even in faraway areas, the team speculated.

When the researchers ran a computer model to calculate the effects of energy consumption, they found that this was indeed the case. Russia warmed up by about 1 degree Celsius, China by 0.5 degrees, and the Canadian Prairies by 0.8 degrees. The phenomenon could explain winter warming patterns previously seen in northern parts of Asia and North America, which had puzzled scientists till now. Roberta Kwok | 28 January 2013

Source: Zhang, G.J., M. Cai, and A. Hu. 2013. Energy consumption and the unexplained winter warming over northern Asia and North America. Nature Climate Change doi: 10.1038/nclimate1803.

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