[AstralStorm]

We don't even have enough metals and plastics to even attempt to do that. It's not an issue, do the back of the envelope calculations yourself.

The more important concern would be immense noise pollution and interference with migrant birds.

[alphydan]

Clearly you haven't done the back of the envelope calculation. Many people have looked at the problem and it's not a trivial one. First, to see how much wind could be harnessed see for ex. [0] or [1]. Assuming 100TW of power, it's ~10^7 turbines. If each one has 50*10^3 kg of steel, it's somewhere between 10^10 - 10^11 kg of steel. 100,000,000 tons if I'm not mistaking. It turns out that Japan produced as much steel on its own, just in 2014. If my estimate is off by a factor of 10, china produced 800 million tons of steel! Glassfibre could be challenging to scale, but it's hardly a scarce resource.

I can also see you have never worked or lived next to a wind turbine. I worked a few yards away from one for a year and the noise was imperceptible inside the building. (Mostly because, when it's moving fast, it's very windy, i.e. very noisy already due to the wind).

Finally, the migrant bird issue is an issue, but it's not hard to solve. Radar and Sonar systems exist to detect migrating flocks of birds and slow down the turbines [3]. But more importantly, buildings, skyscrapers and cars are the number one killer of birds (not turbines). Numbers would change, of course, if we truly tried to extract all accessible, high yield winds. But careful planning and technological solutions would mean that migrant birds would not be more affected than they are today by the human infrastructure.

[0] http://iopscience.iop.org/article/10.1088/1748-9326/8/1/0150...

[1] http://www.pnas.org/content/106/27/10933.full.pdf

[2] https://en.wikipedia.org/wiki/List_of_countries_by_steel_pro...

[3] http://www.detect-inc.com/wind.html,http://www.dtbird.com/

[JBReefer]

I don't get the repeated complaints about noise, they honestly sound really soothing.