Science in the negotiations

How does the UN climate change regime promote science and policy interaction?

Effective interaction between climate science and policy is important for moving climate negotiations forwards. Scientific observations, research and assessment continues to inform the international climate regime, as well as national and regional climate policies. The UN climate change process, under the Convention bodies, relies on scientific information on climate change through a number of work streams.

Systematic observation

Worldwide systematic observation of the climate system is a key prerequisite for advancing scientific knowledge on climate change and advising informed policymaking. Long-term, sustainable systematic observation of the Earth's climate is the foundation for our understanding of climate change and its associated impacts and helps scientists determine future trends.

The Convention calls on Parties to promote and cooperate in systematic observation of the climate system and the development of data archives, including through support to existing international programmes and networks.

Implementation is supported through cooperation, as strengthened by COP decisions and SBSTA conclusions, with CEOS/CGMS Working Group on Climate, Global Climate Observing System, World Meteorological Organization and other partners and relevant organizations.

Parties provide detailed technical reports on systematic observation via their National Communications (NCs).


Climate change research focuses on a wide range of topics, such as earth sciences, climate processes and variability, climate modelling and prediction; climate change impacts, vulnerabilities, risks and extreme events, as well as research on adaptation and mitigation. It covers a broad spectrum of sectors, society, economies and ecosystems and includes cross-cutting and interdisciplinary research.

The Convention calls on Parties to promote and cooperate in research, including through exchange of information and supporting international programmes, networks and organizations and improving research capacities of developing countries.

Implementation is supported through collaboration with a variety of international and regional research programmes and organizations active in climate change-related research including Integrated Assessment Modeling Consortium, Intergovernmental Oceanographic Commission of UNESCO, World Climate Research Programme and other partners and relevant organizations.

The SBSTA research dialogue, mandated by the COP, is a key modality for sharing up-to-date scientific information and Parties’ needs to support the science/policy interface under the Convention.

Cooperation with the Intergovernmental Panel on Climate Change

The IPCC assesses the scientific, technical and socioeconomic information relevant for understanding the risk of human-induced climate change. The IPCC is best known for its comprehensive assessment reports, which are widely recognized as the most credible sources of information on climate change. Cooperation with the IPCC has been further defined and strengthened by several COP decisions.

In addition to its assessment reports, the IPCC also produces shorter special reports and technical papers on specific issues, with a number of them being at the request of the COP or the SBSTA. Special reports are produced under the guidance of one or more working groups following the procedures that are used for writing and reviewing the assessment reports.

In the decision adopting the Paris Agreement, Decision 1/CP.21, the COP invited the IPCC to provide a special report in 2018 on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways (paragraph 21)

Through its Task Force on Inventories, the IPCC carries out important work on developing methodologies for estimating and reporting GHG emissions. The 2006 IPCC Guidelines for National Greenhouse Gas Inventories are used by Parties to prepare their annual emissions inventories, with the “2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories” published in 2019. The IPCC frequently organizes workshops and expert meetings to support the assessment process. It may also co-sponsor workshops if they are considered to be a useful contribution to its own activities.

Periodic review of the long-term global goal

In 2010, the COP agreed on a long-term global goal (LTGG) to reduce GHG emissions so as to hold the increase in global average temperature below 2 °C above pre-industrial levels. The COP also decided to periodically review both the adequacy of this LTGG in the light of the ultimate objective of the Convention and the overall progress towards achieving the LTGG, including a consideration of the implementation of the commitments under the Convention.

This periodic review carried out for the first time in 2013–2015, also considered strengthening the LTGG, including in relation to temperature rises of 1.5 °C. The COP established a structured expert dialogue to support the 2013–2015 review and ensure its scientific integrity. The results of the dialogue between experts and Parties are summarized in the report on the structured expert dialogue (FCCC/SB/2015/INF.1).

The outcome of the 2013-2015 review and in particular its conclusion regarding the LTGG (captured in Decision 10/CP.21, paragraph 4) were contributing factors to Parties' strengthening that goal as reflected and Article 2.1 of the Paris Agreement: “Holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels, recognizing that this would significantly reduce the risks and impacts of climate change”.

The second periodic review of the LTGG started in 2020.

Global stocktake

The Paris Agreement, in its Article 14, outlines a process to periodically take stock of implementation and assess collective progress towards achieving the purpose and long-term goals of the Agreement. This process is known as the global stocktake (GST) and will be conducted by the CMA in a comprehensive and facilitative manner and will cover adaptation, mitigation and means of implementation. It will also be conducted in the light of equity and the best available science.

Parties also agreed in Paris to hold the first GST in 2023 and, every five years thereafter unless otherwise decided by the CMA. The outcome of the GST will inform the updating and enhancing, in a nationally determined manner, of Parties’ actions and support in accordance with relevant provisions of the Paris Agreement. Additionally, the outcome of the GST will enhance international cooperation for climate action.