Increasing gaps between materials demand and materials recycling rates: A historical perspective for evolution of consumer products and waste quantities.

Advancements in product design towards increasingly more compact and efficient systems have created challenges for recycling and materials recovery due to lack of appropriate infrastructure and mechanisms for collection as well as lack of appropriate materials recovery mechanisms and processes for discarded consumer goods. During the period from 1960 to 2015, the world population has increased from about 3 billion to over 6 billion. During the same period, the municipal solid waste quantities have more than doubled globally (from 1.5 million tons/day in 1960 to 4.0 million tons/day in 2015). Due to relatively short use times, especially for high tech consumer products, the number of obsolete products and waste quantities have been increasing exponentially. The American Chemical Society has identified 44 of the 118 elements in the periodic table as endangered and to become extinct in their ore forms within the next 80 years. Nine elements are in serious threat of extinction in the next 100 years, 7 are in rising threat from increasing use elements, and 28 are in future risk of supply. Some elements used in high tech products and industrial applications (e.g., cordless power goods, LCD displays, wind turbines, magnets, rechargeable batteries, smartphones) have shown significant oscillations in their prices during the last decade. Price oscillations for some elements are likely to occur more frequently and with increasing amplitudes in the coming decades as their availability is jeopardized due to increasing demand as well as political and economic challenges for materials supply. Mechanisms for establishing effective waste management and recycling infrastructures for discarded products, similar to that of supply chain management, are needed for sustainable use and management of available material ores on Earth's crust that can support the infusion of technology and use in consumer products.