Think you know about climate change? Think again. You may know that the climate has changed naturally over time, causing oddball events like Europe’s Little Ice Age. You may even know that human-induced greenhouse gas emissions are causing additional changes to the climate.
However, though temperatures appear to be rising, the climate is actually far more complex than any global mean temperature. A new study from the National Center for Atmospheric Research (NCAR) shows that heat emissions from urban areas do far more than warm up urban residents: they can impact the climate on a much wider scale as well.
Beyond the Urban Heat Island
Cities tend to be warmer than the surrounding countryside, in part because of the urban heat island effect. All of those dark, constructed surfaces keep and radiate heat, causing the temperature of the city to rise. However, a study published in January 2013, in the journal Nature Climate Change explored an additional avenue for climate change: urban heat release.
There is more to the urban impact on climate than just the prevalence of blacktop. Human activities emit heat, and this leads to heat emissions from urban areas. When you turn on your car, you emit heat. When you heat your living room, your home leaks heat into the air around it. All these factors contribute to a change in the local climate.
Why Were Climate Models Not Quite Right?
In the new study, Aixue Hu and his colleagues analyzed climate models and found that, in certain regions, the models were off. Though they could have attributed this to variation in the model, they decided to add another factor: heat emissions from cities. When they ran the climate models again, they discovered that their new scenarios matched life much more closely. Somehow, cities were causing changes in the global climate.
Decoding Science. One article at a time.