One of the ways to address climate change concerns is the use of renewable energy sources (solar or wind farms). However, a study by Lee Miller and David Keith from Harvard shows that wind turbines can also affect local warming.
The underlying idea of how to reverse global warming is to reduce the release of so-called greenhouse gases. They are generated primarily by the burning of fossil fuels. Of course, not every alternative to these fuels is adequately advantageous from an energy and economic point of view. We need to evaluate technology in terms of cost and benefits.
One factor associated with wind power plants is the ability to influence local temperatures. It causes mixing of air on and above the surface. Some extreme critics have even claimed that getting wind energy can be as bad as burning coal in the short term.
What did the climate model show?
Lee Miller and David Keith have decided to fill the gaps in our knowledge by simulating a rather unlikely scenario in which the United States produces all the electricity needed through wind power.
Scientists have prepared a detailed climatic model of the US. There virtual wind turbines have been installed in areas with more intense winds. Their number was set to produce half the terrawatt of electricity, which would cover the demand of the whole country.
The result of the simulation by the end of the century is interesting. It showes an increase in continental temperature in the United States by about 0.24 ° C in turbine areas. Within the region, this number was higher by 0.5 °C, at some points even by a full one degree Celsius. This is roughly in line with previous measurements made near real wind turbines.
Changing the temperature is more noticeable at night than during the day. It is because the warmer air being mixed from the height towards the cooling surface during the night hours of the turbine. What is important, however, is that the wind turbines alone do not generate any heat that they emit into the atmosphere. It is because they only affect the flow of air.
Local versus global warming
Scientists are trying to estimate the climatic benefits of turbines from a global perspective. It is clear that while the temperature change caused by air turbines is purely local, the effect of reducing greenhouse gas emissions is global . This means that wind turbines at one point are a global asset.
The local effect of the turbine ends when you turn it off. But the warming caused by greenhouse gases is steadily increasing and lasting for centuries. The global climate change is probably a much more catastrophic scenario than expected local warming from wind power plants.
It is also advisable to compare the values with the expected temperature increase of 4.9 degrees Celsius if humanity continues to increase emissions. Even with a rapid reduction in emissions by the middle of the century, fossil fuel burning will increasingly have an impact on warming than wind farms.
On the other hand, it is unclear what impact wind power would have on US agricultural production. Possible consequences, however, we can be reduce or eliminate by the appropriate location of wind turbines.
“Wind power plants overcome fossil fuels with a reasonable degree of long-term environmental impact per unit of energy produced,” the researchers write. But nothing is free or wind energy. They add, “While these impacts differ in many important respects from the effect of greenhouse gases on the climate. We should not neglect them.”