How much aviation in total, including the military, actually contributes to atmospheric pollution is not very clear or defined.

TMC's intensified engagement, represented by activities and achievements such as those described below, is being carried out with a view toward: 1) improving fuel efficiency to reduce emissions of CO2, which is considered as a cause of global warming, 2) making exhaust emissions cleaner to help abate atmospheric pollution and 3) pursuing energy diversification to limit the use of fossil fuels, particularly that of petroleum.

It began more than 20 years ago when the classifications of Gross (1980) and James and Trendall (1982) helped us understand that Lake Superior-type iron formations are evidence of an atmosphere that became increasingly oxidizing during Proterozoic time--the great rust age that remains to this day the best example of atmospheric pollution by living organisms-and from this realization was born the field of atmospheric and oceanic geology (Berner 2001; Holland 2002).