Hoping they'll convince Honolulu restaurants that environmentally friendly business decisions can attract more customers, several Punahou students are about to unveil their own eco-stamp of approval.

Their philosophy is one of simple genius — or maybe peer pressure: Any restaurant that meets minimum sustainability practices — such as using biodegradable food containers instead of foam ones — would receive a window sticker and be listed as a certified green business.

Green-minded diners would then vote with their forks.

The program is called LEAF, for Leaving Earth A Future, and was created by nine students at Punahou's Luke Center for Public Service and attorney Greg Kim, who volunteers at the center as a mentor.

So far, the students have signed up five restaurants: Red Ginger Café, The Wedding Café, town, Mocha Java Cafe and Kaka'ako Kitchen.

Kim, a 52-year-old corporate attorney who specializes in start-up businesses, thought of the concept a few years ago.

"I often thought for restaurants, that if you took a branding approach to them, you could make them do the right thing," he said. "It's sort of gentle coercion. The idea was why don't we rate restaurants on how green they are and publish the results?"

The carrot for restaurateurs is increased profit.

"If you do the right thing, you will gain business," Kim said. "Doing good means you will do well."

PROJECT BEGINNINGS

The students began their project last summer by researching the various changes restaurants could make. This summer, armed with a sustainability checklist and application forms, they started knocking on doors.

They asked restaurants to do at least three things: recycle, use biodegradable food containers and utensils, and buy locally when possible.

At first, sophomore Kristen Ige, 15, was intimidated by the search.

"I was really nervous," she said. "It's something I never thought I would do. I never thought about actually going to a restaurant and asking them. But a lot reacted well. They were interested."

When she started on the LEAF project, Ige imagined that persuading people to live greener lives was a pitch she would somehow have to make to everyone. But the project taught her an alternative.

"I thought it was more about getting everybody to do something," she said. "I thought making a difference in the world would be to change each individual. But it's easier to change certain parts, like a restaurant."

More bang for the buck.

"For me changing one restaurant, I affect a lot of people, but they don't have to do anything but eat," she said.

HAPPY TO HELP

The idea was a perfect fit with Kaka'ako Kitchen, said Billy Bal, the restaurant's operations manager. The popular restaurant, which only serves takeout orders, had already been making greener changes, Bal said.

This summer, Kaka'ako Kitchen started switching from foam containers to plates that are biodegradable and can be recycled, switched from foam cups to cardboard cups and found an eco-friendly replacement for the nearly 4,000 plastic bags used each month, Bal said.

"We changed our plastic bags to ones that break down completely," he said. "Those guys will break down into compost, and that's just beautiful."

The switch increased prices by an average of 4 cents per meal.

The restaurant liked working with the students. It viewed the experience as an example of good community service.

"We really like taking care of the land and why not help the kids?" Bal said. "It's a good thing to support if we can, and help them learn about the environment and business practices and philosophy."