About This Opportunity
Plans and strategies underpinned by transparent evidence and informed by the best available science will be more effective in contributing to the implementation of the Paris Agreement. This approach, in turn, can make the NDC attractive to investors, as a robust, data-driven development approach reduces uncertainty around the plan’s impacts and its contribution to the Paris Agreement temperature goal. Ensuring the NDC is Informed by Science ultimately facilitates successful implementation.
The Intergovernmental Panel on Climate Change (IPCC) conducts comprehensive assessments based on the latest scientific research, which is widely regarded as the best available science on climate change and, therefore, serves as a critical reference for policymakers. Their latest Synthesis Report finds that to achieve a Paris-aligned global emissions trajectory, global emissions need to peak by 2025 and reduce by 43 per cent by 2030 (with methane emissions specifically needing to reduce by about a third) and 60 per cent by 2035 relative to the 2019 level, reaching net zero carbon dioxide emissions by 2050. These findings are also reflected in the first Global Stocktake (GST), which drew heavily on the work of the IPCC to formulate its outcomes and recommendations.
The IPCC has also set out global carbon budgets. These cumulative emissions limits must be met to achieve the Paris Agreement’s temperature goal. Cumulative emissions ultimately influence atmospheric warming, so aligning NDCs with the best available science on this topic ensures alignment with the Paris Agreement’s temperature goal. Focusing on cumulative emissions also highlights the benefits of early action, as reductions made in earlier years have lasting benefits throughout targeted emissions reductions, making emissions reductions easier in later years.
There are several recent IPCC reports that countries may wish to consult when developing the mitigation portion of their NDC, including:
- IPCC AR6 Synthesis Report (2023)
- IPCC AR6 WG3: Mitigation of Climate Change (2022)
- IPCC AR6 WG1: The Physical Science Basis (2021)
- IPCC Special Report: Global Warming of 1.5oC (2018)
In addition to the IPCC, numerous organizations working at a sectoral level also provide science that can inform NDCs. See “Opportunity: Exploring Sector-Specific Opportunities.”
Reflecting the Global Stocktake
The importance of utilizing the best available science to inform NDCs is highlighted in the GST. Key points include:
- Paragraph 6: “Commits to accelerate action in this critical decade on the basis of the best available science, reflecting equity and the principle of common but differentiated responsibilities and respective capabilities in the light of different national circumstances and in the context of sustainable development and efforts to eradicate poverty”;
- Paragraph 39: “Reaffirms the nationally determined nature of nationally determined contributions and Article 4, paragraph 4, of the Paris Agreement and encourages Parties to come forward in their next nationally determined contributions with ambitious, economy-wide emission reduction targets, covering all greenhouse gases, sectors and categories and aligned with limiting global warming to 1.5 °C, as informed by the latest science, in the light of different national circumstances“.
The following strategies could help to implement this Opportunity:
Introducing carbon budgets:
Countries may wish to integrate national-level carbon budgets into their NDC and can use the global-level IPCC carbon budgets to inform the setting of these cumulative emissions limits – see “Chapter 2 of Global Warming of 1.5oC”. This should be a collaborative process involving all government ministries and sector stakeholders to ensure plans and targets are well understood and “Mobilizes All-of-Government and All-of-Society”. Engaging national experts in this process can help support understanding of the findings, ensure findings are accurately reflected, and ensure the most relevant findings to the country are considered.
Reflecting mitigation efforts identified by the IPCC and other organizations, such as IEA, IRENA:
The IPCC includes key assumptions in its Paris-aligned global emissions trajectory, such as significant sectoral transformations that need to occur. Similarly, organizations like the IEA and IRENA have set out sectoral mitigation pathways aligned with the Paris Agreement temperature goals, as detailed under “Opportunity: Exploring Sector-Specific Opportunities”. It is important that, in reflecting these findings, countries consider which are appropriate to their national circumstances. This can be done collaboratively with government ministries and sector stakeholders – see “Route: Mobilizes All-of-Government and All-of-Society”.
Providing information on how the NDC has been informed by science (including the GST):
Countries may wish to provide information on the underlying evidence for the following elements: national mitigation targets, sectoral targets, key mitigation actions/priorities, planned emissions trajectories, and/or carbon budgets. Providing this information improves the transparency and credibility of the NDC (“Route: Technically Sound and Transparent Documents”), which can help attract investment (“Route: Unlocks Finance”). Some elements of this are included in the ICTU – see “Route: Technically Sound and Transparent Documents” for more information on ICTU.
Using and enhancing national-level evidence and data:
This is discussed in detail under “Route: Technically Sound and Transparent Documents.”
Country Examples
The UK has set a series of five-year carbon budgets that it must meet to stay in line with a trajectory to net zero. The level of these carbon budgets is advised by the UK’s Climate Change Committee, an independent public body responsible for holding the government to account for climate action. In the “Advising on the level of the UKs carbon budgets”, the CCC primarily utilized the work of the IPCC as the scientific basis. (Source: “Carbon Budgets”, Department for Energy Security and Net Zero).
New Zealand’s Vision Mātauranga policy ensures the science and innovation potential of Māori knowledge is incorporated into national climate action planning. New Zealand’s Climate Change Response Act is also informed by the IPCC’s Special Report on global warming of 1.5°C. It has legislated a domestic target to directly contribute to the Paris Agreement’s temperature goal. (Source: “New Zealand’s first Nationally Determined Contribution”, UNFCCC).
Further Resources
The following guidance and tools can further support Ensuring the NDC is Informed by Science.
1.5°C National Pathway Explorer (Climate Analytics, No date)
Climate Analytics’ 1.5°C National Pathway Explorer is a tool designed to help countries explore different pathways towards achieving the goals of the Paris Agreement, particularly limiting global warming to 1.5°C above pre-industrial levels. The tool allows users to analyze various scenarios, including emission reduction trajectories, energy sector transitions, and policy measures, to understand the implications for their national climate targets.
State of Climate Action 2021: Systems Transformations Required to Limit Global Warming to 1.5°C (WRI, 2021)
This report provides a comprehensive overview of the current status of global climate action and the transformations needed to limit global warming to 1.5°C above pre-industrial levels.
Climate Action Tracker (Climate Action Tracker, No date)
This resource gives countries an indication of the “sufficiency” of their target. This is based on alignment with an emissions trajectory compatible with the Paris Agreement temperature goal. “Sufficiency” is estimated in relation to an estimated “fair share” contribution for each country. The findings of this resource can act as a starting point for understanding how close/far the previous NDC target is from a 1.5°C-aligned trajectory. Still, it is important to note that there is no singular accepted estimation of “fair share contributions”; this is simply one way of estimating it.
FAst Scenario Screening Tool (FASST) (European Commission Joint Research Center, 2018)
FASST is an air quality integrated assessment model to support the design of air pollution abatement policies by means of scenario analysis related to: a) health (mortality, morbidity), b) agricultural crop yields, and c) radiative forcing of short-lived climate pollutants.
Carbon Budget Calculator (Carbon Budget Calculator, No date)
This resource allows countries to explore carbon budgets at a global and national level to understand how much emissions need to be reduced to meet the Paris Agreement’s temperature goal. This resource uses a population-based method of dividing the global carbon budget between countries.
Long-Range Energy Alternatives Planning System (LEAP) and Integrated Benefits Calculator (IBC) (SEI, US Environmental Protection Agency (EPA), and University of Colorado 2017)
LEAP is a software tool for energy policy analysis and climate change mitigation assessment that can be used to track energy consumption, production, and resource extraction in all sectors of an economy. The Integrated Benefits Calculator (IBC) is a new application of the LEAP system that combines emissions scenarios from LEAP with output from a global atmospheric chemistry transport model, producing national-scale estimates of avoided premature deaths and crop losses. LEAP-IBC also estimates the climate benefits of addressing short-lived climate pollutants (SLCPs), adopting air pollution reduction strategies and implementing greenhouse gas mitigation.
European Monitoring and Evaluation Programme/European Environment Agency Air Pollutant Guidebook (EMEP, EEA, 2023)
This joint EMEP/EEA air pollutant emission inventory guidebook supports the reporting of air emissions data under the UNECE Convention on Long-range Transboundary Air Pollution (CLRTAP) and the EU National Emission reduction Commitment Directive. It provides expert guidance on how to compile an atmospheric emissions inventory.
SAP Temperature Pathway Calculator (CCAC, No date)
The SAP Temperature Pathway Calculator requires input of all pertinent emissions that impact temperature. It then computes the temperature changes in yearly increments for the entire globe and four latitudinal bands.
Global Transportation Roadmap (International Council on Clean Transportation, 2019)
The Global Transportation Roadmap model, created by the International Council on Clean Transportation (ICCT), predicts greenhouse gas emissions, short-lived climate pollutants, and other air pollutants originating from the road transport industry
Solid Waste Emissions Estimate Tool (SWEET) (US Environmental Protection Agency, 2023)
The SWEET tool, developed by the United States Environmental Protection Agency, measures greenhouse gas emissions, short-lived climate pollutants, and other air pollutants from the municipal solid waste sector.
How This Links to Other Routes
Ensuring NDCs are informed by science and that the evidence underpinning the NDC is transparently communicated improves the credibility of the NDC. This results in the following key linkages. Navigate to these to read more:
Route: Technically Sound and Transparent Documents
NDCs transparently supported by the best available science and data provide more certainty about their contribution to the Paris Agreement temperature goal.
Route: Unlocks Finance
Science and evidence-driven NDCs are more credible and more likely to attract investment.
Additional Opportunities
The NDC 3.0 Navigator presents eight examples of Opportunities countries can pursue to enhance NDC ambition through alignment with the Paris Agreement temperature goal.
