Mar 31, 2011 07:43 GMT  ·  By

For years, the aircraft industry has been considered one of the main polluters, and also one of the primary contributors to exacerbating the effects of global warming. A new study now indicates the contrails are the most hurtful of its effects, not the release of carbon dioxide.

Airplanes burn massive amounts of highly-processed fossil fuels such as kerosene to stay aloft, and this process results in the emission of large quantities of dangerous greenhouse gases, such as for example carbon dioxide (CO2).

Counter-intuitively, carbon emissions are not the primary threat the aviation industry poses to the environment. The contrails aircraft leave behind are a lot more damaging, because they can exert a significant influence on cloud formation patterns in the atmosphere.

Equally as important in this equation is where the aircraft burn their fuel. In some areas, they can cause large numbers of big clouds, which go on to influence the local climate patterns a lot more significantly and directly than CO2 ever could.

This was demonstrated recently, in a paper published in the scientific journal Nature Climate Change, Wired reports. The main conclusion of the study is that the actual pollution aircraft generate is only one component of the effects this industry has on the world.

Other means through which aviation influences climate include the emission of particulate matter in the upper atmosphere, the production of clouds through the creation of contrail water vapors, and the creation of dangerous chemicals known as nitrogen oxides.

The thing about contrail-produced clouds is that they are not helping the planet. While clouds forming at low altitudes tend to reflect sunlight back into space, and contribute to planetary cooling, those that develop at high altitudes actually have an insulating effect.

This means that sunlight-produced heat hitting Earth's surface can no longer escape through the atmosphere, because high-altitude clouds act like mirrors. This is one of the mechanisms underlying the greenhouse effect, which leads to global warming.

Experts say that there are currently few solutions we might apply to the aviation industry for reducing both emissions and the formation of contrail-caused cirrus clouds. Changing the types of fuels we use could be a great start.

However, biofuel technology is not nearly developed enough to be used on aircraft, electricity is out of the question (as battery demands would be massive) and hydrogen fuel cell technology is still a few years away.