What I find amazing is that these environmental hippies take all sorts of liberal arts courses, but can't pass their science classes.
Here are some questions for hippies:
The global warming hippie: What percentage of the atmosphere is composed of Carbon Dioxide? Which element composes the bulk of the air that we breath?
The anti - clean coal hippie: What is the primary element that coal is composed of? What types of bonds does it form with Oxygen? How many Oxygen atoms can bind to it?
The acid rain hippie: What is the normal pH of water? What pH would make it acid rain? What would be the pH of normal rain if there were no cars and factories to pollute our air?
Feel free to add your own Chemistry and Physics questions. It would be fun to ask these on the street.