One of the more interesting things I found out back in the days of school was that CO2 imissions take close to between 50 to 100 years to reach the Ozone Layer. Any destruction now can in fact be traced back to such time as the Industrial Revolution. This being said all the 'Greener' methods now will improve thing latter on down the track hopefully for our kids. Hence the claim the Hole in the ozone will infact close back up again.