Markoz wrote on Nov 18^th, 2011 at 1:10am:

If you replace 1 old aircraft, that emit 100 units of pollution into the atmosphere, with 5 modern aircraft, that emit 30 units of pollution into the atmosphere, then you are still releasing more pollution into the atmosphere than you were back when you were using that single aircraft (5 x 30 = 150). So the point that CoolP makes is still valid. More pollution IS being emitted into the atmosphere today, than it was many years ago. The only difference is that it takes more aircraft to do it. I'm not using exact figures because I don't know what they really are.

Well it depends. Its like the car vs. motorcycle story.

See, yes a Motorcycle might 75mpg (per-say) but the car gets 35mpg, yes, the motorcycle might burn less gas than teh car, but the car has more emissions standards.SO the motorcycle may be emitting more toxic gases and carcinogens than the car, but less CO2 than the car. So would you rather has less CO2 or less ozone, sulphur, and other things?

So yes, you're replaced 1 plane with 5, the original made 100, the new five make 130. But you get to take 1,000 passengers (each plane holds 200) with the new five, and only burn 130. But with the old, you only carry 200 for 100. So that equates to a 2:1 (two passengers to each until of pollution) with the old, and 7.69:1 with the new five. Thats how a 747 going from LAX to JFK can be more effecient than a single person in a car. You get 467 people to new york over a shorter distance than 1 person over a longer (ditance & time).