Recycling involves prosessing used materials into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy useage, reduce air pollution (from incineration) and water pollution(from landfilling) by reducing the need for "conventional" waste disposal and lower greenhouse gas emitions as compared to virgin production. Recycling is a key component of modern waste reduction and is the third component of the "Reduce, Reuse, Recycle" waste hierarchy.
