Why do people still burning joss paper?

I hate it when people start burning joss paper,considering the pollution could be done .In my country and own religion,they burn joss paper like no tomorow.My fren is heavily influenced by his dad,so he is VERY superstitious.I start arguing with him whenever we talk about religion and tradition practice.He said burning joss paper is a tradition practice and cant be avoided.Why do ppl still burning joss paper?Cant they see the pollution?Why there is no action taken? I can see people trying to save earth but there isnt anyone stoping joss paper burning?