Wasted heat from large cities affects temperatures in distant regions

The waste heat generated by large cities can affect temperatures in areas hundreds of miles away by changing wind patterns in the upper atmosphere, a study has found.

Scientists have estimated that the heat released into the atmosphere from buildings, cars and factories could play a significant role in the warming – and the cooling – of locations in other countries.

Using computer models of how heat is transported around the globe, the study published in the journal Nature Climate Change says that waste heat from 86 urban centres in the northern hemisphere could in theory raise temperatures of parts of North America and northern Asia by as much as 1C.

The same models suggest that other parts of the northern hemisphere, notably Europe, could actually become cooler at certain times of the year by up to 1C as a result of the heat affecting the direction of high-altitude winds such as the jet stream.