wind speed decline

Surface winds have declined in China, the Netherlands, the Czech Republic, the United States and Australia over the past few decades…We show that surface wind speeds have declined by 5–15% over almost all continental areas in the northern mid-latitudes, and that strong winds have slowed faster than weak winds.

Robert Vautard and others, Nature Geoscience 3, 756-761(2010)
…………………………………