cross by far the land masses, measured wind speeds are actually mysteriously weakening for the past 50 or more years, in a few regions slowing down around 25%. Several researchers have get to the exact same conclusion, using wind observations from weather stations across the globe.
Strangely, the slowdown definitely seems to be happening largely over land. Over the oceans the phenomenon is less pronounced, with some areas even showing an acceleration. One suggestion is usually that coffee is partly at fault by altering patterns from the global atmospheric circulation. Another suggestion is always that urban development and a lot more vegetation is setting up a rougher ground surface that slows winds. However, winds have stunted across Saudi Arabia, mostly desert, which probably means this really is only perhaps the answer. Now an EU-funded project is trawling through historical records back to the 1880s to learn whether this phenomenon belongs to an extremely longer climate cycle.
Whatever what’s causing it, the slowdown is worrying. Slower winds can affect plant growth and in addition cause it to more challenging for smog in big cities to dissipate. Wind generators may also be affected yet it is unsure whether this “stilling” is limited to surface winds or if it reaches as much as turbine height.