Life cycle analysis

I have had to teach Life Cycle Analysis in recent years. This is a tool to calculate the impact of a particular product based on the energy and environmental damage involved in raw materials, manufacture, transport and disposal. I was surprised by one that I saw that put polystyrene cups ahead of waxed paper cups. The latter are lighter and so less fuel is used in transport. The balance on that one might have shifted now that waxed paper cups might be becoming more recyclable. In the case of the paper towels, they need raw materials and are heavy to transport. The wet paper won't be recycled. So this is another example of where a paper product might seem to be a better option than using electricity, but masking the fact that more electricity and fossil fuels were used in manufacture and transport. I think people prefer paper towels because they seem to give drier hands faster.