As usual, the trick is to show them how the environment would be cleaner
with a free market than with government control.
The biggest polluter in the US today is the government. It can't
be sued and is simply ignores the EPA directives that everyone else must
obey.
Private property is the best way to preserve the environment. People
always take better care of something they own. It is tough to resell
a polluted piece of land.
People would also be legally responsible for harming another person's property.