© Pixabay/Free-PhotosThe average terrestrial wind speed has slowed down half a kilometre per hour every decade since the 1960s.
Few people have probably noticed, but the world's winds are getting slower. It is something that cannot be picked up by watching the billowing of dust or listening to the rustle of leaves on nearby trees.
Instead, it is a phenomenon occurring on a different scale, as the average global wind speed close to the surface of the land decreases. And while it is not affecting the whole earth evenly, the average terrestrial wind speed has decreased by 0.5 kilometres per hour (0.3 miles per hour) every decade, according to data starting in the 1960s.
Known as 'stilling', it has only been discovered in the last decade. And while it may sound deceptively calm, it could be a vital, missing piece of the climate change puzzle and a serious threat to our societies.
Dr Cesar Azorin-Molina, a climatologist at Sweden's University of Gothenburg and lead researcher of the EU-funded STILLING project, believes there is an urgent need to determine the causes of stilling in a changing climate.
While 0.5 kilometre per hour might barely seem enough to ruffle any feathers, he warns that
prolonged stilling will have serious impacts.'There are serious implications of wind changes in areas like agriculture and hydrology, basically because of the influence of wind on evaporation,' said Dr Azorin-Molina. 'A declining trend in wind speed can impact long-term power generation, and weaker winds can also mean less dispersion of pollutants in big cities, exacerbating air quality problems and therefore impacting human health.'
Comment: Less than a month ago Storm Sebastian killed three people across Germany with hurricane-force winds. In August five people died after a violent bow echo storm system hit Poland.