Corporate travellers well understand the issue here - many non-domestic flight routes are absolutely unavoidable and yet the science tells us that the alpine terrain that we all so value is under significant threat from expanding concentrations of CO2 in the atmopshere. From an economic point of view, less fuel burnt should also reduce the pressure on air ticket prices whilst the almost inevitable future carbon taxation surcharges would surely be less punitive on flights and carriers with lower emissions. Air France managed the 50% reduction by using a new fuel mix, reducing the weight of the non-structural features of the aircraft and by using flight techniques that meant better fuel efficiency. With the recent launch of the Boeing Dreamliner which uses composite materials to lessen weight and increase fuel efficiency, the race is well underway to reduce our air flight impact on the mountains and environment that we all so need.