A couple of the parks that I frequent are very close the MSP International Airport. While I am out birding at Fort Snelling State Park or the Minnesota Valley NWR planes are always flying over head on their landing approach. I often wonder on what the long term affect of these planes are on the wildlife. The first thing that I would guess might have an affect is the noise. The noise is deafening as the planes pass over, often shaking the ground itself. The noise bothers me but does it affect the wildlife? I am sure that it has some affect but in many cases it appears that the wildlife can get used to the noise so that it does not phase them. I have seen snowy owls, which have sensitive hearing, sitting next to airport runways as planes are taking off. The owls can leave if they want but they chose to stay at the airport, it reminds them of the arctic with a lot of open space and prey.
Planes also emit pollutants. The burning of jet fuel produces several greenhouse gasses. Most of the exhaust is carbon dioxide, about 70%. The remainder of the exhaust is water, nitrogen oxide and particulate emissions that are produced from the sulphur that is in most jet fuels. None of these emissions are good, however airplanes contribute only around 3% of the total environmental pollution. Since they are really a form of mass transit they may actually help to reduce pollution. Imagine the amount of pollution of a jet going from MSP to Dallas with 100 passengers compared to the pollution of those 100 people driving in 80 different cars the same distance. Still there are better forms of mass transit. In places in Europe and Asia, where they do not have crazy tea baggers, they have high speed rail. Since HSR typically uses electricity instead of burning hydro carbons it is cleaner. Maybe some day we will get to the point here in the US where doing what is right will be more important then doing things because you get money or power.