[Terry]

Terry asked the Naked Scientists:

With all compressed air cylinders throughout the world would there be a massive change in atmospheric pressure if it were to be released all in one go?

Terry, in Ipswich

What do you think?

[paul.fr]

I think we have had this question before, and it was never answerd. So for what it's worth...

I don't think it would. For a start atmospheric pressure is not a constant value, although, what is constant is the mass of "dry air". That being air that has had the water vapour removed from it. The constituants of that air, by mass percentages is:

Nitrogen 75.51
Oxygen 23.15
Argon 1.28
Other 0.06

What we also know is that these gasses (when water vapour is removed) have a partial pressure, those being: (about)

Nitrogen 750 mb
Oxygen 230mb

So just the two main constituents contribute 980 mb out of the 1000mb that make 1 bar, the largest gas left is water vapour that can contribute anything from 5mb to 30mb of pressure. So you could argue that the one gas that could (and does) change the atmospheric pressure, is water vapour.

I think two laws that may cover some of this are Avogadros and Daltons.

[Bored chemist]

There would be a change but it would be tiny.
Also, since all the air in the bottles was part of the atmosphere before, all releasing it would do is bring the pressure back to whatever it was before thye compressed the air in the first place.