If you have ever looked out across a city on a frosty winter morning, the question might have occurred to you (as it has to me): What happens to all that heat when it eventually gets out of the buildings, cars and other fossil fuel burning sources?
Does it add anything to the temperature outside?
Some climate modelers now think it does. Despite the fact that heating energy in big cities is sparsely dispersed over the planet as a whole, amounting to only about 0.3 percent of the total energy coming from warmer regions to cooler regions in winter via weather and ocean currents, this human-made heat could be enough to affect the jet stream and other big atmospheric circulation systems. This means big heated cities could be altering the weather thousands of miles away in the winter.
That's the conclusion of a group of researchers from Scripps Institution of Oceanography, Florida State University, and the National Center for Atmospheric Research.
The researchers added the anthropogenic winter heat to climate models to test out whether it could explain real world winter warming patterns seen in some areas that had before confounded scientists. The results of the study appear in the Jan. 27 issue of journal Nature Climate Change.