Joint implementation (JI) is one of three flexibility mechanisms set out in the Kyoto Protocol to help countries with binding greenhouse gas emissions targets (so-called Annex I countries) meet their obligations. JI is described in Article 6 of the Kyoto Protocol. Under Article 6, any Annex I country can invest in an emission reduction project (referred to as a "Joint Implementation Project") in any other Annex I country as an alternative to reducing emissions domestically. In this way countries can lower the costs of complying with their Kyoto targets by investing in projects that reduce greenhouse gas emissions in an Annex I country where reducing emissions may be cheaper, and then using the resulting Emission Reduction Units (ERUs) towards their commitment goal.
A JI project might involve, for example, replacing a coal-fired power plant with a more efficient combined heat and power plant. Most JI projects are expected to take place in so-called "economies in transition," noted in Annex B of the Kyoto Protocol. Currently Russia and Ukraine are slated to host the greatest number of JI projects.
Unlike the case of the Clean Development Mechanism, the JI has caused less concern of spurious emission reductions, as the JI project, in contrast to the CDM project, takes place in a country which has a commitment to reduce emissions under the Kyoto Protocol.
The process of receiving credit for JI projects is somewhat complex. Emission reduction projects are awarded credits called Emission Reduction Units (ERUs), which represents an emission reduction equivalent to one tonne of CO2 equivalent. The ERUs come from the host country's pool of assigned emissions credits, known as Assigned Amount Units, or AAUs. Each Annex I party has a predetermined amount of AAUs, calculated on the basis of its 1990 greenhouse gas emission levels. By requiring JI credits to come from a host country's pool of AAUs, the Kyoto Protocol ensures that the total amount of emissions credits among Annex I parties does not change for the duration of the Kyoto Protocol's first commitment period.
The formal crediting period for JI was aligned with the first commitment period of the Kyoto Protocol, and did not start until January 2008 (Carbon Trust, 2009, p. 20). In November 2008, only 22 JI projects had been officially approved and registered. By 2012, it is expected that the total number of ERUs generated by JI will be around 300 million. This estimate is based on values taken from project plans, and makes no adjustment to account for delivery in practice.
Russia accounts for about two-thirds of these projected savings, with the remainder divided up roughly equally between Ukraine and the EU's New Member States. Emission savings include cuts in methane, HFC, and N2O emissions.
In December 2012, ERU prices crashed to a low of 15c before recovering to 23c after news that EU’s Climate Change Committee was to vote on a ban of ERUs from countries that have not signed up to a second commitment period under the Kyoto Protocol. In January 2013, Bloomberg reported that Emission Reduction Unit prices declined 89 percent in the 2012 year.
See also 
- Assigned amount units
- Emission Reduction Unit
- Removal Units
- Certified Emission Reduction
- Clean Development Mechanism
- Flexible Mechanisms
- Obtaining ownership of land by productive use
The Third Period ( Phase three ) of the EU - Ts is expected to start by the end of 2012 The future of the JI is expected to be decided by the committee of the UNFFCC.
- UNFCCC Joint Implementation on the UNFCCC pages.
- Foundation Joint Implementation Network Host of the Joint Implementation Quarterly (JIQ) newsletter.
- The original Kyoto Protocol
- For more on JI see http://unfccc.int/kyoto_protocol/mechanisms/joint_implementation/items/1674.php
- Annex B of the Kyoto Protocol identifies 12 economies in transition: Bulgaria, Croatia, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, the Russian Federation, Slovakia, Slovenia, and Ukraine.
- "JI Pipeline Analysis and Database". UNEP Risoe CDM/. 2012. Retrieved September 19, 2012.
- The initial assigned amount of AAUs is equal to a country's 1990 level of greenhouse gas emissions, less five percent, multiplied over five years. Each AAU is worth 1 ton of C02 equivalent. This formula is set forth in Article 3 Paragraph 1 of the Kyoto Protocol. The actual emission limitations for each Annex I Party are listed in Annex B of the Kyoto Protocol.
- To illustrate, suppose the Kyoto Protocol only had three Annex I parties, countries A, B and C, each having 100 AAUs for the whole first commitment period. This would mean that the total amount of credits at the beginning of the first commitment period would be equal to 300. Now suppose that A hosted a JI project for B, resulting in 10 credits-worth of emissions reductions. A would have to convert 10 of its AAUs to ERUs and transfer them to B. So in the end, A would have ten less credits, or 90 AAUs (100 AAUs minus 10 converted ERUs); B would have ten more credits (100 AAUs plus 10 ERUs from the project), and country C would remain with its 100 AAUs. The total number of credits at the end of the first commitment period would be the same -- 300.
- Carbon Trust (March 2009). "Global Carbon Mechanisms: Emerging lessons and implications (CTC748)". Carbon Trust website. Retrieved March 31, 2010.
- Allan, Andrew (12 December 2012). "U.N. offsets crash to 15 cents ahead of EU ban vote". Point Carbon. Retrieved 16 December 2012.
- Bloomberg (1 January 2013). "European carbon permit prices cap another losing year". The Age. Retrieved 14 January 2013.