In order for the manufacturing system to be sustainable in the very long-run, the inputs have to be recycled from previously used goods. With the possible exception of some particularly plentiful resources such as iron and silicon, all other raw materials are being depleted at a rate that most will be gone within a century. Some resources, such as oil, may become too expensive for mass use in the next decade. In addition, mining causes serious environmental damage, as well as polluting precious water supplies.
A report by the Natural Resources Defense Council estimates that if 75% of the solid wastes in the U.S. were recycled, that 2.3 million jobs would be created. If we assume 100% recycling, then we could estimate about 3 million jobs.