Artificial leather
Artificial leather might look like it is better for the environment, since no animals need to be killed to make it. The problem with artificial leather is different: When the item of clothing is no longer used, it is thrown away.  Many plastics take a long time to decay. That way, the plastic part may get into the sea, where animals such as birds and fish eat it. The chemicals used to make artificial leather are toxic, and can lead to pollution.