&quot;Stop flying&quot; is, to say the least, an extreme measure. Especially when there are so many other things you can stop that have at least as much impact on the environment (i.e., consuming beef). I also take issue with your statement that &quot;flying is one of the human activities that we don&#x27;t have to do.&quot;<p>Flight connects foreign countries and unites cultures. A hundred years ago, you would never experience a remote island in the pacific, and there would certainly not be an international tourist industry on that island. But flying makes it possible to go through a door, sit down for 18 hours, and emerge in a completely different part of the world, surrounded by a totally new culture. You benefit from that, and so does the culture you visit. Even if the economics are asymmetrical, such that you can visit the island but the islanders cannot visit you, at least you can provide a window for them to experience your culture in the same way you experience theirs.<p>With literally <i>any</i> culture in the world available to you at a moment&#x27;s notice, flying promotes the idea that we are all one species, one people, one family. The importance of this cannot be understated. Learning about other cultures allows you to empathize with them, to see them as fellow humans instead of some hypothetical out-group. Flying turns the world into a global cultural melting pot, instead of a disjoint collection of conflicting groups.<p>The importance of this cannot be understated. Globalization, for all its problems, is primarily a uniting force, and certainly one that promotes world peace. The more you learn about your fellow Earthlings, the more you experience other cultures, the more you realize that <i>human culture</i> is one unified work of art, and to harm one is to harm them all.<p>So no, flying is not something that &quot;we don&#x27;t have to do.&quot; It is, quite literally, one of the primary forces contributing to relative world peace.