Litterbugs Stink
This world was created for us and other creatures to live on. Although, some people make it seem like the world is a giant trash bag by littering. Some examples of littering that I see more often are throwing trash out the window, dropping trash without noticing, and leaving litter wihtout throwing it away.
However the world is not a giant trashbag and should be kept clean. We should do everthing we can to keep it clean. Some simple things that we can do include picking up trash we see and warning people if they drop trash without knowing. Littering is a very bad thing a we should not tolereate it.
Humans as one should do everything they can to try to clean up the planet and stop other people from littering. If we can't stop littering, then the world might end up like the one in Wall-e. When the world is covered in litter, you can blame the litterbugs.