Our economy craves critical metals or “technical nutrients” to build the carbon-fighting solar panels and electric cars we need, and the work-and-lifestyle-sustaining electronics we want and enjoy.

“Technical nutrients” are essential substances that spur growth, including economic growth, if used in the right way. Sustainability book Cradle to Cradle defines a “technical nutrient” as non-biological, which is something that doesn’t biodegrade safely into nature and should be used, reused and never wasted in our industrial economy.