My days of flying ended when I read the study conducted after 9/11 when all US flights stopped temporarily. The difference in weather patterns was immediate and profound. The fact that the carbon dioxide is released 33,000 ft up in the air where it lingers amplifies the the problem because the carbon dioxide stays for months up there until it slowly circulates to our oceans and plants where it can be removed from our atmosphere. Condensation trails are the other culprit as they act like blankets trapping heat. Airline companies have been altering flight paths to avoid condensation trails which form under specific conditions. They know that this is a big problem with airplanes so they spend more on fuel to divert flight paths which only solves half the problem. Most of my "friends" have abandoned me because I don't fly as I have missed weddings and reunions. When I travel now I explore places on my home continent which has virtually endless new areas to see and experience. It never ceases to amaze me when I see selfish people travel thousands of miles just to soak their feet in warm tropical water for a few days only to return home while missing countless treasures in their own backyard.