'Wind power causes climate change' shown to be so much hot air
The signal is less than the noise
The localised weather effects of wind-farms are just that – localised weather effects rather than climate-change engines in their own right, according to new research from Europe.
When studies emerged in 2012 suggesting local wind-farm-warming effects, they raised speculation that the effects might not be purely local.
Two particular studies are of interest in the debate over the non-local impacts, models from 2004 and 2008 by David Keith et al which suggested that the wind farms' effects on wind direction might lead to surface temperature shifts as much as 0.5° in some locations, along with precipitation changes. The abstracts for these studies can be found here and here.
According to new modelling led by Robert Vautard of the Laboratory for Climate and Environment Sciences in France, the effects are lost in the noise, or in the more cautious terminology of a scientist, the impacts of wind farms “remain much weaker than the natural climate interannual variability”.
The study focussed on modelling the interactions between wind turbines and the atmosphere, and is published in Nature Communications (abstract here).
While agreeing with David Keith's suggestion that large-scale wind does impact wind direction (“a weak, but robust, anticyclonic-induced circulation over Europe”, the abstract says), Vautard's group concludes that the large-scale impact is limited and will remain so for the foreseeable future.
According to Science Daily, Voutard assumed that Europe's deployment of wind power would reach 200 GW by 2020.
While Voutard's paper finds that some regions might experience both a slight temperature increase (0.3°C in some places) and a possible loss of a few percent of annual precipitation, both of these effects would only be significant in winter.
These changes – as noted, less than natural variations – Voutard attributes to the wind direction impact, a slight northward deflection of westerly winds in Western Europe, as well as local effects where wind farms are at their most dense. ®