A new study of the effect of local air mixing at the site of a wind farm says nothing about wind energy and global climate, and casts no doubt on all the other studies that find wind power is one of the best ways to address climate change. Local air mixing has nothing to do with climate, because no heat or heat-trapping gases are being added to the atmosphere.
As happens all too often at the intersection of science and politics, the results of a technical journal article have been picked up by the popular press and misconstrued through a type of “telephone game,” in which the resulting press articles bear little resemblance to the original scientific article. The most recent incident involves a scientific article hypothesizing that wind turbines can have very small, localized impacts on local temperatures being misconstrued to make it sound as though wind plants could contribute to global climate change, which is not true and is actually physically impossible–since operating a wind farm adds no heat or heat-trapping gases to the atmosphere.
Those who have followed this topic may remember that similar misreporting occurred just a few months ago, as chronicled in this excellent article on the Guardian newspaper’s blog: http://www.guardian.co.uk/environment/blog/2012/feb/07/wind-farms-climate-change-weather
To promote understanding of this issue and improve the public dialogue, AWEA would like to set the record straight on the science by correcting some of the misreporting on this most recent study:
Wind plants do not contribute to climate change, and in fact they are one of the leading technologies preventing climate change by avoiding fossil fuel use and the emission of greenhouse gases. Much of the popular reporting on this topic has confused the issue of climate change, which is a major global phenomenon driven by greenhouse gases actually warming the earth by altering the earth’s energy balance, and a speculative, small, short-lived, localized impact on the weather that could possibly be caused by wind plants slightlyaltering how air mixes around wind plants. It is important to emphasize that wind cannot contribute to climate change because any localized change in how air mixes is not a forcing of the climate or a change in the Earth’s energy balance. In contrast, greenhouse gases that are emitted into the atmosphere by producing and burning fossil fuels stay in the atmosphere and continue warming the planet every day in perpetuity.
In fact, the localized weather changes that the most recent study hypothesized were caused by wind farms may have actually been long-term warming caused by greenhouse gases or other changes in the climate. A comparison of NASA climate data from 2003 and 2011 – the time period covered by the most recent study that found a 0.72 degree Celsius localized change in weather in parts of Texas – shows that 2011 was a much warmer year than 2003 across much of North America.
In fact, across a massive area stretching from Texas to eastern Canada and down to South America, temperatures in 2011 were several degrees Celsius warmer than they had been in 2003 (which most people will recall from press coverage of last year’s extreme weather) as confirmed by NASA temperature data for 2003 and 2011. This region-wide warming is several times larger than the localized weather impact the study purports to attribute to wind plants, making it highly suspect at best that the study was able to isolate a localized impact from a much larger climate trend, particularly when the vast majority of this region contains no wind plants yet experienced a similar level of warming.
All studies have found that any impact wind plants may have on local weather is trivially small. A primary conclusion of the study that has generated the recent press articles was that wind plants can cause a slight increase in nighttime temperatures and a slight decrease in daytime temperatures. All studies have found that any localized impact on the weather would be trivially small, less than a degree Celsius and localized only to an area immediately around a wind project. It is also important to point out that nearly all human activities can have an impact on localized weather phenomena, and the impacts of farming, building buildings, flying airplanes, and reforestation or deforestation are typically much larger than any localized impact found in this study.
“The warming estimate applies specifically to this particular region, and covers a time when wind farms were expanding rapidly … The estimate should not be considered directly applicable for other regions and landscapes, nor should it be extrapolated over a longer period of time, as the warming would likely plateau rather than continue to increase if no new wind turbines are added. The warming is also considered a local effect, not one that would contribute to a larger global trend.”
We are glad scientists feel free to ask interesting questions such as those posed by this study. AWEA supports scientific efforts to fully understand the environmental effects of wind power and all other forms of energy development. However, as AWEA CEO Denise Bode said today in a statement, “We caution against people with an agenda who may try to misconstrue this study for their own purposes.”
We wish the public dialogue about such studies accurately characterized the results and did a better job of putting them in context. When one does that, it is clear that wind energy remains one of our best tools for avoiding the negative environmental and climate change impacts of continued reliance on fossil fuels.