Recycling processes waste materials into new products. Aluminum cans become new cans. Glass bottles become new bottles. Paper becomes cardboard. Plastic is trickier. Each material has its own cycle, its own economics, and its own limits.

The benefits are real. Recycling aluminum saves about 95 percent of the energy needed to make it from raw ore. Recycling paper saves trees, water, and energy. Recycling glass reduces mining and landfill use. These savings add up. But recycling is not a cure-all. It works best when materials are clean, sorted, and in demand.

The system has weaknesses. Plastic recycling rates are low, around 9 percent globally. Many municipalities collect mixed plastics that have no market. China stopped accepting most imported recyclables in 2018, disrupting global flows. Contamination in recycling bins sends loads to landfills. The most effective strategies are reducing consumption and reusing products. Recycling is the third option, not the first.

Common materials

• Aluminum
• Glass
• Paper and cardboard
• Steel
• Certain plastics