One thing that is easier to do is burning garbage. There are two main ways to incinerate waste. The first is to create or harvest a fuel from the waste, such as methane gas, and burn the fuel. The second is to burn the waste directly. The heat from the incineration process can boil water, which can power steam generators. Unfortunately, burning garbage pollutes the air. Also, some critics worry that incinerators destroy valuable resources that could be recycled.