“Our climate just can’t tolerate widespread frequent flying,” said Dan Rutherford, who directs the council’s aviation program. “At some level we need to figure out, collectively, which flights are necessary, and which are luxuries.” I am an international student and I took a long way flight around 4 times a year from US to China. It is around 13 hours flight. I have never thought about the guilty part before I read this article. I don’t like flight because it is very uncomfortable and expensive from my angle. But I have never felt guilty before. Now I am, the fossil fuel it used and CO2 it creates are increasing dramatically. Sometimes in the domestic airlines, I can have some other choices but the flight is convenient so I chose, I never thought about environmental problems caused by this. I saw a data that how manys fight we have in the whole planet. I think one part we should think twice before we order our flight tickets, also we should find green material to replace aviation gasoline.