Gaunty I think you may have a good point here, whilst I am reluctant to promote any ideas that are damaging to the aviation industry (as it is not only my bread and butter but my sons as well), the facts speak for themselves regarding global warming, greenhouse effect / gases etc. The climate is changing, the earth is warming up, oceans are warming up and there will be more Katrinas , Ritas and huge chunks of antarctica breaking off and floating away.
Just as aircraft engine noise reduction was the big deal in the 70's and 80's , so will aircraft engine emmission be the big deal in the coming decades. The sooner the old coal burners are sent to the Mojave and turned into scrap metal and beer cans the better. Clean and fuel efficient aircraft are the best legacy that we can give to future generations.
By the way mattyj pls review paper on greenhouses gases at this website:
http://www.agu.org/eos_elec/99148e.html
you may then reconsider your view on CO2 as being a benign and harmeless gas in the atmosphere.