produce authentic benefits and are genuinely "additional" activities that would not otherwise have been undertaken. Organizations that are unable to meet their emissions quota can offset their emissions by buying CDM-approved Certified Emissions Reductions (CERs). However, the economy behind the carbon offsets generate a new type of consumption in the complexed carbon economies. According to the World Bank State and Trends 2020 Report, 61 carbon pricing initiatives are in place or are scheduled for implementation globally. These include both emission trading schemes (like cap-and-trade systems) as well as carbon taxes and, although these initiatives represent markets for carbon, not all incorporate provisions for carbon offsets, but instead place greater emphasis on achieving emission reductions within the operations of regulated entities. The original compliance carbon market was initiated by the Kyoto Protocol's Clean Development Mechanism (CDM). Signatories to the Kyoto Protocol agreed to mandatory emission reduction targets, enabled (in part) by carbon offset purchases by higher-income countries from low- and middle-income countries, facilitated by the CDM. The Kyoto Protocol was to expire in 2020, to be superseded by the Paris Agreement. The Paris Agreement determinations regarding the role of carbon offsets are still being determined through international negotiation specifying the "Article 6" language. Compliance markets for carbon offsets comprise both international carbon markets developed through the Kyoto Protocol and Paris Agreement, and domestic carbon pricing initiatives that incorporate carbon offset mechanisms. Many entities exist within the voluntary carbon market (see offsetguide.org for more information). For example, carbon offset vendors offer direct purchase of carbon offsets, often also offering other services such as designating a carbon offset project to support or measure a purchaser's carbon footprint. In 2016, about US$191.3 million of carbon offsets were purchased in the voluntary market, representing about 63.4 million metric tons of CO2e. In 2018 and 2019 the voluntary carbon market transacted 98 and 104 million metric tons of CO2e respectively. These programs generate carbon offset credits provided that an emission reduction or removal activity meets all program requirements, applies an approved project protocol (also called a methodology), and successfully passes third party review (also called verification). Once carbon offset credits are generated, any buyer may purchase them; for example an individual may purchase carbon offsets to compensate for the emissions resulting from air-travel (see more on Air-travel and Climate). Global market In 2009, 8.2 billion metric tons of carbon dioxide equivalent changed hands worldwide, up 68