How does science inform climate policy and action under the UNFCCC?
The UN climate change process, through the Convention bodies, relies on scientific information on climate change submitted by many contributors. Organisations such as the IPCC and the WMO have been requested by Parties engaged with the Subsidiary Body for Science and Technological Advice to intermittently update it and the Conference of the Parties on their work. Other organisations such as the International Institute for Applied Systems Analysis and Group on Earth Observations also regularly make submissions that inform the SBSTA of work in specific relevant areas.
This information, along with Parties experiences in events such as the Research Dialogue and Earth Information Day, and workshops, is considered in Informal Consultations in the first week of the biannual sessions of the two subsidiary bodies. Here, scientific and technical representatives of Parties decide what information they will include in their SBSTA Conclusions text to be forwarded to plenary negotiations during the second week of the annual COP session. These conclusions are considered by Heads of Delegation of all Parties as they negotiate the legally binding Decisions texts of the COP, CMA, and CMP.
Parties can then use decisions to guide national and regional policies and decision making, creating Nationally Determined Contributions, National Adaptation Plans, and other climate plans and communications informed by the best available science. Parties return to the next session with experience of implementing decisions and requests for the research and observation communities to expand the knowledge on specific topics that have been identified as requiring further understanding to advance climate action.
Several workstreams play a vital role in facilitating scientific input to the UNFCCC. There are:
Research and Systematic observation (RSO)
Worldwide systematic observation of the climate system provides the information to advance scientific knowledge on climate change, its impacts, and future trends. Global measurements of interconnected systems such as the atmosphere, ocean, cryosphere and biosphere are combined to create an increasingly comprehensive overview, and to detail specifics, of the Earth system.
Climate change research is frequently informed by systematic observation and focuses on a wide range of topics, such as earth sciences, climate modelling and prediction adaptation, mitigation, financial flows, and social implications. It provides insights into these topics relevant to many sectors including society, economies and ecosystems, and includes cross-cutting and interdisciplinary research.
The Convention (negotiated in 1992) calls on Parties to promote and cooperate in research, including through the exchange of information, developing data archives, supporting international programmes, networks and organisations and improving the research capacities of developing countries. Since then, Parties have agreed on many conclusion texts that have gone on to inform decisions.
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 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). This special report became the basis for efforts to limit global temperature rise to 1.5 degree C. The COP has repeatedly expressed its appreciation to the IPCC for the presentation of its assessment reports and requested additional special reports.
The latest sixth assessment report informed the outcome of the first global stocktake and other work under the UNFCCC. The continuing reports released by the IPCC are considered by Parties during informal consultations on RSO.
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.
During the first periodic review (PR1) the COP decided to establish the Structured Expert Dialogue (SED) to facilitate dialogue with experts and provide scientific input to support the review. PR1 contributed to strengthening the LTGG, reflected in 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 (PR2) of the LTGG started in 2020 and concluded at COP 27 in 2022, with outcomes reflected in 21/CP.27.
Informal consultations on the PR are held under the SBSTA during PR review cycles.
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.
Parties agreed in Paris in 2015 to hold the first GST in 2023 and, every five years thereafter unless otherwise decided by the CMA. The first GST concluded in at COP 28 in 2023 with the adoption of decision 1/CMA.5. 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 will enhance international cooperation for climate action.