The environmental analysis is surprisingly complicated, according to an article in Slate, “Public bathroom dilemma: Paper or air?”

What is one or two paper towels or 30 seconds of hot air compared to the emissions belched from cars stacked on I-84? But consider the following: So far this year Americans have used 1.8 million tons of paper towels and tissue, according to the American Forest & Paper Association, an industry group. There are approximately 3 million hand dryers installed in the country and most run for 30 seconds around 100 times a day, according to World Dryer Corp., one of the country’s leading manufacturers. That’s 690 billion watts of electricity every day — enough power to run an estimated 280,000 homes for an entire year.

The responsible choice seems to be the third option at the very end of the article . . .