Schools are often a hub for food waste: Parts of lunches brought from home don’t get eaten, or perhaps the cafeteria menu isn’t all that appetizing. Experts say tons of food from school meals is wasted each year. Not only does that cost schools, but it’s also a major contributor to methane in landfills. Recovery, recycling and composting have cut food waste at many schools and provide a learning opportunity for students. Public schools serve more than 30 million lunches each day, according to federal figures. A vast majority of them come from the National School Lunch Program through the U.S. Department of Agriculture.