At its first session, in 2012, the ADP adopted the agenda, as set out in document FCCC/ADP/2012/2, paragraph 13, initiating work under two workstreams: workstream 1 on matters related to paragraphs 2 to 6 of decision 1/CP.17 (agenda item 3(a)) and workstream 2 on matters related to paragraphs 7 and 8 of the same decision (agenda item 3(b)). Throughout 2013 and 2014, the ADP has continued its work under both workstreams including through a series of in-session round-table discussions and workshops, as well as technical expert meetings and briefings, taking into account submissions from Parties and observer organizations as invited by the ADP.

The first session of the ADP in 2015 was held in Geneva (ADP 2-8). The ADP concluded its work in Paris on 5 December 2015 (ADP 2-12). 

The COP, by decision 1/CP.17, launched a process to develop a protocol, another legal instrument or an agreed outcome with legal force under the Convention applicable to all Parties (also referred to as the 2015 agreement), which shall be adopted at the twenty-first session of the COP, in 2015, for it to come into effect and be implemented from 2020.

According to decision 2/CP.18, the ADP is to consider elements for a draft negotiating text no later than at its session to be held in conjunction with COP 20, in December 2014, with a view to making available a negotiating text before May 2015.

Decision 1/CP.19, adopted in Warsaw, requested the ADP to further elaborate, beginning at its first session in 2014, elements for a draft negotiating text, taking into consideration its work, including, inter alia, on mitigation, adaptation, finance, technology development and transfer, capacity-building and transparency of action and support.

In Lima, through decision 1/CP.20, Parties acknowledged the progress made in elaborating the elements for a draft negotiating text as contained in the annex to the decision. Parties further requested the ADP to intensify its work, with a view to making available a negotiating text for a protocol, another legal instrument or an agreed outcome with legal force under the Convention applicable to all Parties before May 2015.

Through the same decision, Parties requested the secretariat to communicate the negotiating text to Parties in accordance with provisions of the Convention and the applied rules of procedure, while noting that such communication will not prejudice whether the outcome will be a protocol, another legal instrument or an agreed outcome with legal force under the Convention applicable to all Parties.

The COP, by decision 1/CP.17, noted with grave concern the significant gap between the aggregate effect of Parties' mitigation pledges in terms of global annual emissions of greenhouse gases by 2020 and aggregate emission pathways consistent with having a likely chance of holding the increase in global average temperature below 2 °C or 1.5 °C above pre-industrial levels.

Though the same decision, the COP decided to launch a workplan on enhancing mitigation ambition to identify and explore options for a range of actions that can close the ambition gap, with a view to ensuring the highest possible mitigation efforts by all Parties.

In Doha, through decision 2/CP.18, the COP decided to identify and explore in 2013 options for a range of actions that can close the pre-2020 ambition gap, with a view to identifying further activities for its plan of work in 2014, ensuring the highest possible mitigation efforts under the Convention. 

Decision 1/CP.19 requested the ADP to accelerate its conduct of the workplan on enhancing mitigation ambition to identify and to explore options for a range of actions that can close the ambition gap, with a view to ensuring the highest possible mitigation efforts by all Parties in the context of decision 1/CP.17, paragraphs 7 and 8. Parties also decided to accelerate activities under the workplan on enhancing mitigation ambition in accordance with decision 1/CP.17, paragraphs 7 and 8, by, inter alia, intensifying, as from 2014, the technical examination of opportunities for actions with high mitigation potential, including those with adaptation and sustainable development co-benefits, with a focus on the implementation of policies, practices and technologies that are substantial, scalable and replicable, with a view to promoting voluntary cooperation on concrete actions in relation to identified mitigation opportunities in accordance with nationally defined development priorities.

The secretariat has set up a portal which presents information on cooperative initiatives undertaken around the world at various levels by governments, international organizations, civil society, and business to reduce emissions.

In Lima, the COP, by decision 1/CP.20, reiterated its resolve to enhance ambition in the pre-2020 period in order to ensure the highest possible mitigation efforts under the Convention by all Parties. The COP further decided to continue the technical examination of opportunities with high mitigation potential, including those with adaptation, health and sustainable development co-benefits, in the period 2015–2020 and requested the ADP to make recommendations in relation to further advancing the technical examination process, including the periodic assessment of the technical expert meetings, to the COP at its twenty-first session.