One of the perks of living in the desert Southwest is that we get to see dramatic expanses of sky. Out here, it's easy to see dark thunderheads build miles and miles away or watch sheets of rain come marching across a mesa.

Most often, however, I find myself counting the number of contrails that have left stripes across the sky.

Contrails are the white trails that you see behind planes. They're made of condensation, ice particles, and vapor from airplane exhaust. But they often linger in the skies, and ultimately become artificial cirrus clouds—which are indistinguishable from real clouds.

I never really paid attention to contrails until a friend mentioned them one day. As the contrails turn into man-made clouds, they end up affecting our weather, usually bringing rain and storms.

In fact, scientists got more evidence about the impact that contrails have on the weather after September 11, 2001 when planes were grounded for a week. They found that air travel was directly responsible for higher temperatures.

According to a Live Science article, NASA has documented that cirrus cloud cover has increased in the U.S. by one percent per decade. Researchers think that it accounts for our warmer temperatures.

Still, it's worth noting that contrails are just a small part of the climate change spurred on by air travel. Far more damaging to the environment are the carbon emissions and greenhouse gases caused by jetliners.

The good news is that an eco-friendly jet may be on the horizon. Scheduled to launch in 2015, a new British prototype, called the easyJet ecoJet, promises to emit 50 percent less carbon dioxide, and 75 percent less nitrous oxide—both of which are greenhouse gases.

I hope that this is just one of many more green innovations we see from the aviation industry.

Meanwhile, those contrails keeps right on forming, and and it's easy to see why our individual carbon footprints get bigger every time we hop on a plane.