To all of us, the solutions for stopping climate change seem pretty simple. First, the activities from which greenhouse gases are produced and released into the atmosphere – mainly represented by the use of fossil fuels – need to be altered or completely eliminated. Instead we can choose from a multitude of alternatives to standard fuels but, naturally, not every one of them will be equally beneficial.
Costs and benefits are the criteria used for evaluating new technologies. Wind turbines, for example, can affect local temperatures because they increase the mixing of air at their surface and above. Of course, they aren’t as bad as coal plants but they make us seriously think about how they can change the local temperatures.
David Keith and Lee Miller from Harvard decided to help us improve our knowledge on the subject by simulating how the US would look if all the energy would come from wind power. For this, they resorted to a climate model of the United States at high-resolution. They placed plenty of virtual wind turbines in the middle third of the country because that’s where winds blow the most.
In doing so, they ensured almost 0.5 terawatts of electricity which is exactly what the US demands. The results showed them that the temperature on the continental US got 0.2 degrees Celsius warmer. The region where the wind turbines were found had a temperature higher with 0.5 degrees Celsius.
This temperature change is higher at night than during the day because the Sun overwhelms the influence of the turbines through its driven convection and surface warming. At night, on the other hand, the air is calmer and the turbines mix warmer air down the cooling surface. So, this means that this effect is instantaneous but also, reversible.