Originally Posted by
A and C
Light aviation contributions to pollution are so small as to be insignificant, I did see figures that suggested that the annual U.K. GA fuel burn was equal to the fuel burn for an hour on the M25 at rush hour.
I don't know the sorce of these numbers but I think it sums up the scale quite well.
The stat I saw was that the total fuel that evaporates from Car fuel tanks via the breathers exceeds total consumption of 100LL across the whole of Europe.