Wind generators work by taking some energy out of the wind and converting it to electricty. If enough generators were placed to power the energy needs of the world, how much energy would be taken from the wind? Would solar heating keep up? Or would it cause global climate change?
Wind is actually degenerated solar energy. So, if somehow we managed to satisfy 100% of our power needs from wind energy, then no additional heat would be released to the enviroment.
You raise a good point. At which point does energy taken negate the energy given by natural motions.
But we’re not at that point yet. Today, here and now, the question you might ask is “How much energy can I take from the wind?” A lot has to do with the efficiency of ‘windmills’ as I call 'em, and the generators attached to 'em.
It’s a relatively well-explored idea, but unfortunately unused. 'Specially in places that are windy, like North Dakota, or places that blow, like Montana. 
Tripler
Why is ND so windy? 'Cause Montana blows and Minnesota sucks!
If we manage to satisfy some significant part of the world’s energy demand through the derivation of usable energy from windmill farms, we have to wonder - what happens if you take 12.5 tera-watts of energy out of the world’s wind systems?
Obviously, the directly affected (where we suck off the energy) winds are slowed down. How does that affect the balance of movement of the air?
Well, I’d think you’d first start seeing changes in the weather.
not trying to be a jerk[sub]TM[/sub] (great general rule by the way) but everyone seems to have simply restated my question. Does anyone have a difinitive answer, or an educated guess, just a guess?, anything?
According to the CIA factbook
http://www.cia.gov/cia/publications/factbook/geos/xx.html
The world consumed 13.93 trillion kWh of electricity in 2001.
According to this website
http://www.ece.umr.edu/links/power/Energy_Course/energy/wind.html
an 8 meter windmill generates about 10000 KWH a year. So you’d need about 1.4 billion of those.
It depends alot on the size of the windmill, how windy the area you put them in is, and how efficient they are. i read recently (cant remember the stats offhand) that new windmills are several times more effective than ones that existed a decade ago. So its hard to say due to the variables on producitivity.
Great. now, does anyone know how much solar enegy gets converted to atmospheric movement?
So how is building a windmill any different than planting a tree, or a building? Wouldn’t all of these remove an equal amount of energy - if not more - from the wind? If so, I haven’t heard of anyone worrying about the effects of a forest on the earth’s climate (regarding wind).
wind is basically moving pressure differences in the air. as solar energy generates heat, the air that is heated ends up having a different level of pressure than the other air, which causes motion.
About .3% of US electricity is generated by windpower and here’s a link showing installation:
http://www.awea.org/projects/index.html
Any sites older than five years or less than 25M capacity per location is far from present cost effectiveness, unless the energy being used is miles from the powergrid.
Cost of generation has declined about 85% in 25 years, and some believe another 30-40% may be possible within this decade. This would require reenactment of the on again off again federal production subsidy .
The newer installations use 1-1.5M capacity units, the towers can be over 200 ft and blade span 300 ft or more. Units of these sizes must be placed 5-9 blade spans apart for the very reason suggested in the OP.