True and false about air traffic and environment

"Air traffic is one of the main environmental hooligans"
The Intergovernmental Panel on Climate Change (IPCC) states that air traffic currently accounts for about two per cent of global carbon emissions – in other words, a relatively small percentage. On
the other hand, air traffic has other problems, such as nitrogen oxide and water vapour emissions and the effects of condensation trails.
When these aspects are included, it is estimated that air traffic accounts for 4.6 per cent of man’s total effect on the climate. As more and more people travel, these figures are likely to rise in the future. The percentage coming from air traffic will probably increase, but the amount depends not only on the aircraft industry but also on how successfully society reduces its other emissions.



"Air traffic has reached its limit when it comes to technically reducing its environmental impact"
Aircraft manufacturers are constantly working to make advances related to the environment. They have developed lighter materials, smarter aerodynamic  designs and better engines. As a result, aircraft are steadily becoming more effective and reducing fuel consumption and thereby emissions. For example, the Airbus 380 has the lowest fuel consumption per seat of all aircraft currently being used in scheduled traffic. Travelling with the A380 is more fuel efficient than going alone in a fuel efficient modern car.

"Air traffic does more damage as emissions are discharged at high altitude"
This is one of the fundamental climate problems for air traffic. When jet propulsion fuel is combusted at an altitude of 10,000 metres, the effect on the climate is greater than it would be if the fuel were combusted on the earth’s surface. The climatic effect of air traffic is due not simply to carbon emissions but also to other factors, such as emissions at high altitude of water vapour, nitrogen oxide and particulates. Researchers do not, however, agree on how much greater the impact at high altitude is compared with near the ground.



"Air traffic will be the last means of transport to change to biofuel"
In 2011, airline companies are expected to operate commercial flights with the traditional fuel mixed with as much as 50 per cent environmentally sustainable alternatives. This will only have a marginal environmental effect, however. If biofuel is to produce a really positive effect on the environment, the production capacity that is needed for a large-scale transition to alternative fuels has to be created. This takes a long time.