Killer Contrails Cooking the Arctic – Radiative Forcing Vital Option in Carbon Offsets
Posted Apr 28 2010 8:00am
Air travel is so much faster than surface transportation that it’s easy to embrace it with the thought, “If I arrive in a fraction of the time of driving or riding the train, it can’t be that bad.” Tragically, it is the very nature of air travel which makes it so damaging to the atmosphere, especially the over the Arctic.
The power of jet fuel lies in its ability to provide tremendous thrust at a wide range of altitudes and an even wider range of temperatures. However, conventional jet engines would be compromised by scrubber technology, such as catalytic converters, to nullify some of the harmful effects of their fumes. Hence, they are allowed to burn jet fuel with no emission controls. That’s bad enough. However, of equal concern is the fact that burning jet fuel not only releases tons of carbon right into the planet’s most vulnerable layers but water in the form of contrails.
Why are contrails such a problem? According to an engineering team at Stanford University, led by Mark Jacobson, jet emissions increase the fraction of cirrus clouds where vapor trails are most prevalent but decrease the fraction in some areas by increasing the temperature and consequently decreasing the relative humidity in the lower atmosphere.
The damage doesn’t stop there, though. The manner in which the atmosphere attempts to respond to the damage from these vapor emissions, contrails, is altered by the heavy carbon content of jet fuel. All told, Jacobson estimates that 15% – 20% of the catastrophic warming seen in the Arctic is caused by the effects of air travel.
Do I advocate terminating the use of jets? Certainly not but we can take steps to slow the damage, such as embracing the use of biofuels and hydrogen in aviation. However, what also can help is a sober accounting of the difference between burning fossil fuels at or near sea level and doing so several miles above the face of the Earth. A handy tool for doing so (and for spending a few dollars to offset the damage from flying) is available through the partnership between Carbonfund.org and jetBlue.
Their carbon offset webpage not only makes it very easy to calculate and purchase offsets from airline flights but includes an option for radiative forcing, the physical phenomenon which causes jet emissions at altitude to be more harmful to the Arctic than emissions at or near sea level. In fact, the radiative forcing option is driven by a simple check box.
Even if you are not yet ready to invest a nominal fee to offset your latest flight, or if you would like to know how much damage will be caused by a future flight, surf over to the flight calculator in the jetBlue section of Carbonfund.org and input your travel cities. The whole process will take about 5 minutes. The results may surprise you.