Carbon markets under international law were first set up under the Kyoto Protocol (1996) and became operational in 2000. The protocol mandated binding reductions in emissions by developed countries, but not in developing ones, and set up three carbon market instruments: Emissions trading -under which developed countries could trade abatements exceeding their mandates with others which fell short; "Joint Implementation" (JI) covering negative carbon generated from individual projects which could be traded between corporates in developed countries; and the "Clean Development Mechanism" (CDM) by which such credits could be generated from projects in developing countries and traded to corporates in developed countries.