Of course, global warming, the universal boogey man, gets the blame
Near-surface wind speeds over landmasses across the planet have dropped by as much as 25% since the 1970s, and climate scientists are taking note. Michael Lucy reports.
The wind isn’t what it used to be. Scientists say surface wind speeds across the planet have fallen by as much as 25% since the 1970s. The eerie phenomenon – dubbed ‘stilling’ – is believed to be a consequence of global warming, and may impact everything from agriculture to the liveability of our cities. It has taken more than a decade for scientists to get a handle on stilling, a term coined by Australian National University ecohydrologist Michael Roderick in 2007.
Roderick had spent years studying a 50-year decline across Europe and North America of a climate metric called pan evaporation. It measures the rate at which water evaporates from a dish left outside. With his colleague biophysicist Graham Farquhar, he found the cause: the sunlight had dimmed due to air pollution. Less light equals slower evaporation.
In 2002, after publishing the explanation in the journal Science, Roderick received a query from Roger Beale, the head of Australia’s federal department for the environment. Was pan evaporation also declining in Australia? “To my embarrassment,” Roderick recalls, “I had to say I didn’t know, because I’d never looked.”
Two years later, he had an answer: the pan evaporation rate was also falling in Australia. It was puzzling, however, as air pollution levels on the continent were lower than those of Europe or North America.
Roderick went back to basics. The rate of evaporation depends on four factors: air temperature, humidity, the amount of solar radiation and wind speed. After another three years of combing through meteorological records, he had pinned down the culprit: “To my absolute surprise, we found the main reason for the drop in Australia was less wind – and by a lot.”
Roderick unearthed other local studies from around the world with similar findings, but till then no one had joined the dots.
He teamed up with Tim McVicar, a hydrologist at Australia’s national science agency, the CSIRO, who was looking for global wind patterns and their effects on evaporation. In 2012 this team – led by McVicar – compiled results from almost 150 regional studies to show stilling was taking place across much of the world.
In Australia in the 1970s, average wind speed a couple of metres above the ground was 2.2 metres per second: in 2017 it was 1.6 metres per second.
Over landmasses from as far north as Svalbard, 1,050 km from the North Pole, to as far south as the coast of Antarctica, “observations show that wind is stilling”, McVicar says.
…
Roderick takes a more telescopic view: air movements are powered by differences in temperature at different places. The bigger the difference between warm and cold air, the stronger the wind. One effect of global warming is to flatten those differences. The poles are warming faster than the equator, winters are warming faster than summers, and nights warming faster than days. “Everything becomes more uniform,” Roderick says.
Full report at Cosmosmagazine.com
h/t to Clyde Spencer
If the wind stops our children just won’t know what tornadoes are. No hurricanes of blizzards either. Derechos will be a thing of the past.
Reverse the windmills NOW before it gets worse than it is! Renewable wind is the answer! Oscillating windmills to save the wind! Do it for the children and their children and even the buzzards!
I think it is due to UWL (Urban Wind Loss). Probably due to placing the anenometer on your back deck.
My personal weather station rarely records wind speeds above 4-5 knots even during a durecho.
Back in the seventies when Climate Science was still a science H H Lamb showed that storms were stronger and more frequent during the LIA gthan in recent times.
The Modtran computer code, which calculates energy deposition for different parts of the planet from greenhouse gases, does, indeed, show that colder regions and colder times (winter vs summer) shows this effect.
Our children won’t know what kites are.
Oh no. And think about the –
polar– seagulls. We must save the seagulls!https://www.theatlantic.com/international/archive/2011/07/an-era-of-tornadoes-how-global-warming-causes-wild-winds/241639/
https://www.seeker.com/global-warming-kicks-up-record-pacific-trade-winds-1768916257.html
https://news.nationalgeographic.com/news/2011/03/110328-earth-storms-winds-global-warming-science-environment/
https://news.ucsc.edu/2008/12/2644.html
IS that you Ivan? Ivan the Russian troll.
Winds, both speed and direction, are determined by atmospheric pressure differences. Look at the wind predictions issued by weather reporting, they show the pressure variables then the predicted wind speed and direction. Heating up or cooling down would have to be changing at different rates to change wind speeds. It’s the pressure!
1. Combined winter wind speeds (at all altitudes) in the northern hemisphere (where it counts) are decidedly stronger than in summer, as detected even in earth rotation (LOD). Low elevation winds are dominant (see Fig. 9 and Table 5: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2003JB002432 ).
2. USI (Urban Still Effect–just made it up) must be taken into account, along with increased forestation (and wind turbines, of course). Trees and skyscrapers are growing.
3. A claimed global increase in humidity must be taken into account.
4. Land temperatures are supposed to increase much faster than sea temperature, which should increase wind speeds.
5. We are being asked to accept a 25% decrease in random (non-directional) wind speeds which integrated have no effect on average atmospheric rotation (zonal — pro grade), when seasonal differences are easily detected.
Some peer review. –AGF
The metric of wind speed depends on what you call wind speed, by what equipment and with what inertial lag to move and integrated over what time scale and what time of day. “Wind speed” is itself, slang. So the slang thing is slowing. Got it.
Less wind would warm the Earth up.
The lighter the wind in the daytime the warmer it is?.
Well, that’s how it works where I live.
And rightly so, probably, in this case.
https://www.washingtonpost.com/news/capital-weather-gang/wp/2018/05/15/northeast-severe-weather-threat-destructive-wind-is-likely-just-in-time-for-evening-commute/
Clearly this is all Exxon’s fault. They must make restitution.
It’s all those bird blenders extracting energy from the wind that’s causing the slow-down 🙂
Perhaps the “stilling” is a cause in the warming. Less cold waters coming up from the depths, more surface waters warming and a strengthening of the thermocline.
Or is it a cover-up of Planet X? By naming it “Climate Change?”
My grandchildren will not know what wind is. Sad
Yes, the Clintons won’t be around much longer nor will that stain on her dress…
OMG short sailboat stocks big time. Time to rake it in.
“Everything becomes more uniform,” Roderick says.
But they can[t have it both ways, If smaller differences between hot and cold results in less winds, they must also result in less intense storms as it’s this same difference in pooled energy that drives storm systems.
Wind is caused by pressure differentials.
I have this crazy theory to explain it. Every wind turbine extracts energy from the atmosphere, and the wind on the lee side of a turbine is slower because of the energy taken out. Over the last 2 decades, hundreds of thousands of wind turbines have been erected, and they have been increasing in size too. Between them they must have a slowing effect on wind speeds around the world. On the face of it that would not seem to make much difference, but could there be a multiplier effect? After all that is no more crazy than the idea that a trace gas could make a significant difference to GMT, because of a multiplier effect.
Granting that winds are produced by temperature differences, then it is true that that GHGs reduce average wind speed. It is a well established fact that greenhouse gases deposit more heat to cool areas than to warm areas. I have checked that out with the Modtran computer code for both temporal (summer vs winter) and latitudinal (tropics vs temperature zones). However, it has its limits. We can never get a windless world. GHGs are not the only source of heat to the atmosphere, and surely not the dominant one. If I gain sufficient curiosity and ambition, I will try to estimate what the limiting effect on wind speed is from GJGs
Bad news for wind power: globally, winds are slowing
With the current state of the QBO, what did you expect?
The world’s winds, like all weather features, are in a state of flux. They’ll NEVER settle into an utterly stable pattern — get used to it!
Changes by cycling solar output changing wind speed.
An insurmountable problem for wind and solar converters is that they cannot be reasonably isolated from the environment, and are therefore only suitable for mission uncritical applications. Unless, of course, they are supplemented with electric storage technology, but how long will China absorb the “green” waste?
Very interesting. Lindzen said that weather is driven by the equatorial-polar temperature gradient. Perhaps this stilling of the wind is due to arctic warming.