The Climate Action Monitor 2025

Annex B. Data gaps, methodology and limitations

Chapter 1

Country GHG emissions estimates

Country-level data is based on emissions inventories reported to the United Nations Framework Convention on Climate Change (UNFCCC). This data is compiled using territory-based and production‑based principles following the Intergovernmental Panel on Climate Change (IPCC) guidelines. The primary data source is the Common Reporting Tables (CRT) submitted by Parties as of 18 June 2025, supplemented by previous national inventory submissions and OECD Annual Quality Assurance (AQA) questionnaire. Since data is not available for all countries or all years, estimates were used to fill gaps. The data sources and methodology used in this publication are summarised below:

• OECD Members: For most OECD countries, GHG emissions data from CRT or other official data sources are available from 1990 to 2022 or 2023. Exceptions include Colombia (1990-2021), Israel (1996, 2003-2022).

• OECD Partners: Significant data gaps remain including major emitters. China has provided official data for seven years (1994, 2005, 2010, 2012 and 2014, 2020-2021), while India has presented data for four years (1994, 2000, 2010 and 2016). There are also gaps for Peru (data missing from 1990-1999), Saudi Arabia (data available for eight years between 1990 and 2012), South Africa (eight missing years between 1990 and 2000) and Indonesia (1995-1999 missing).

• Due to these gaps, aggregates presented in this report are based on a combination of official and estimated data.

To address data gaps, the OECD developed a methodology to impute missing values in a consistent manner maintaining alignment with official reports (Cárdenas Rodríguez et al., 2024[1]). The methodology uses the PRIMAP-hist national historical emissions time series (Gütschow, Busch and Pflüger, 2024[2]), which are adjusted to official estimates for imputation. The methodology is as follows:

• If no official data are available, the PRIMAP series is used.

• When two official data points exist, missing values between them are interpolated using PRIMAP trends and rescaled to ensure the interpolated series passes through the official data points.

• For years beyond the range of official data, the PRIMAP level difference is added to the most recent (or earliest) official point.

• Total emissions including land use, land-use change and forestry (LULUCF) is obtained by adding Total emissions excluding LULUCF and LULUCF and estimates. The other sectoral levels are derived by applying sectoral shares to the total emissions estimates.

• Energy subsectors estimates are obtained using shares from the IEA database of GHG emissions estimates matching the energy module of 2006 IPCC Guidelines.

GHG emissions have been converted using Global Warming Potentials from the sixth IPCC assessment report (AR6 GWP) (Forster, 2021[3]).

Global GHG emissions estimates

In the 2025 Monitor edition, the calculation of global GHG emissions undertook two key modifications. First, international bunkers uses data from the IEA database of GHG emissions estimates matching the energy module of 2006 IPCC Guidelines. Second, the LULUCF bookkeeping component uses data from (Friedlingstein et al., 2025[4]) based on the approach used in (UNEP, 2024[5]).

As a results of these adjustments and the integration of additional official GHG data through Common Reporting Tables (CRT), emissions estimates are slightly lower than those published in the previous year. Consequently, both editions of 2024 and 2025 Climate Action Monitor show emissions of 55 Gt CO₂e in their respective latest available years - 2022 and 2023. However, the trend of continuously increasing emissions since 2020 is maintained across editions.

GHG emissions are calculated as:

${GHG}_{World}= {Country GHG}_{Excluding LULUCF}+ {International Bunkers}_{}+LULUCF Bookkeeping$

Table B.1. Detailed estimates of GHG emissions targets for 2030 and 2050 (Gt CO₂e)

	2023	2030	2050
UNEP estimated global emissions under current policies		57 (53-59)*	56 (25-68)*
Global emissions if targets achieved	54.5	52.5 (48.5-54.5)*	20.1 (19.0-21.2)
LULUCF adjustment	7.5	8.1	8.1
˗ LULUCF bookkeeping (outside inventories)***	3.6	4.2	4.2
˗ LULUCF inventories (2023 value projected forward)	-3.9	-3.9	-3.9
International bunkers (aviation and maritime)	1.2	0.9	0.0
Total countries (in GHG. Inventories, excl. LULUCF)	49.7
Total countries (in GHG Inventories incl. LULUCF)		43.5 (39.5-45.5)	12.0 (10.9-13.1)
˗ IPAC	37.9	29.6	7.5 (6.6-8.5)
OECD	14.5	9.3	0.7 (0.6-0.8)
OECD Partners	23.4	20.3**	6.8 (5.9-7.9)
1.5°C Consistent		33 (26-34)	8 (5-13)
2°C Consistent		41 (16-24)	20 (16-24)

Note: *Sourced from (UNEP, 2024[5]). The estimate found in (UNEP, 2024[5]) for projected emissions in 2030 under Unconditional NDCs has been proportionally adjusted to align with the World emissions estimate.

**Excludes Saudi Arabia since its 2030 NDC cannot be quantified.

***Projected values use the average of the last ten years using Global Carbon Budget 2024.

GHG emissions targets

To enable comparison of countries’ NDC emissions targets, the OECD developed a methodology to estimate GHG emissions targets for 2030 as physical emissions targets (Pizarro et al., 2024[6]). The methodology is as follows:

If the country NDC target is defined for 2030 in physical terms (i.e. in tonnes of CO₂e), the target is maintained.

Otherwise, targets are put into physical emissions levels for 2030 by applying transformations to country-level data to derive 2030 emissions targets in physical terms; these include adjustments for GDP, population and other transformations presented in (Pizarro et al., 2024[6]).

Countries' NDC targets are not directly comparable due to differences in coverage of sectors, gases and GWP. For comparison, emissions and targets were adjusted to AR6 Global Warming Potential (GWP) and covering all GHGs as follows:

• Physical targets are adjusted to AR6 GWP by multiplying the original target by the ratio of the total 2023 GHG emissions (AR6) over the GHG emissions within the NDC scope.

• GHG emissions outside of scope are imputed. This applies to China only as it uniquely covers CO₂ in its NDC. To this end, non-CO₂ gases are projected within a range.

Global emissions for 2030 were taken from (UNEP, 2024[5]), with the 2030 value used for emissions under unconditional NDCs, and adjusted proportionally to the world emissions estimate use. Emissions in 2050 emissions were projected based on the assumption of countries achieving their net-zero targets as proposed. Emissions for countries without a net-zero target were assumed to be at the same level as 2023, with a range of +/- 10% (e.g. Iran, Azerbaijan and others).

Moreover:

• EU-27 countries were considered as a bloc that reaches climate neutrality by 2050, as per the EU Climate Law; individual countries’ targets differ since some do not have a net-zero target.

• Emissions for countries with a net-zero target later than 2050 are estimated based on a linear trajectory to their target year (e.g. China by 2060 and India by 2070) for the calculation of the 2050 Targets Consistency Gap.

• Emissions were adjusted based on differences in LULUCF estimates based on (UNEP, 2024[5]), and these differences were assumed to remain constant through 2050.

• International aviation and shipping are assumed to reach zero emissions by 2050 as per international agreements by the International Air and Transport Association and the International Maritime Organization. This reduction is assumed to be linear from 2023 to 2050.

• 2030, 2035, and 2050 emissions consistent with 1.5°C and 2°C increase pathways are sourced from (UNEP, 2024[5]).

Targets Monitoring

In this edition, visualisations on distance to target indicators based on (Pizarro et al., 2024[6]) are used to provide insights on whether countries are on track to meet their climate targets over different time horizons: the NDC Delivery Gap and the 2050 Targets Consistency Gap. For these calculations, a base year of 2019 was used, the year when countries formulating their NDCs (2.0), prior to the temporary drop in emissions caused by the COVID-19 pandemic. For IPAC aggregates, targets were harmonised to a common sectoral and gas scope. For individual country analysis, targets were kept in the scope defined in each country’s NDC. For harmonisation between emissions and targets, all values were converted into AR6 GWP.

These are calculated as follows:

${ Delivery Gap}_{}= \left(\frac{{GHG emissions}_{2023}-{Linear trend to NDC target}_{2023}}{{Linear trend to NDC target}_{2023}}\right)\times 100$

${2050 Target Consistency Gap}_{}= \left(\frac{{NDC target}_{2030}-{Linear trend to 2050 target}_{2030}}{{Linear trend to 2050 target}_{2030}}\right)\times 100$

Chapter 2

The OECD set of indicators is based on historical observational data and forward-looking projected data. The observed historical data has been collected and recorded and goes back as far as 1979 (Maes et al., 2022[7]). Meanwhile, the forward-looking projected data goes up until 2100, comprising anomalies for the 2030s, 2050s, 2070s and 2090s relative to the 1995-2014 climate reference period (Maes et al., 2025[8]). The strength of this year’s report lies in the expansion of the indicator set to incorporate forward-looking projections, enabling the reader to look back and forward in time. Historical indicators reflect what has happened, while forward-looking indicators project what will happen.

Notwithstanding, historical and forward-looking indicators are based on different underlying data sources and methodologies. These indicator datasets should therefore be interpreted with caution since these are not directly comparable. Nevertheless, the 46 years of historical data combined with 86 years of forward-looking projections offer the basis for a long-term analysis of climate change, highlighting the exposure of populations, croplands, forests, and urban areas to climate-related hazards. These indicators illustrate an alarming trend: climate change impacts are already visible by analysing historical trends and are projected to worsen in many regions across the world, under various climate scenarios. For a complete description of the methodologies behind historical and forward-looking indicators, please see (Maes et al., 2022[7]) and (Maes et al., 2025[8]).

Information on disaster events and their related costs has limitations due to inconsistent reporting by national governments and in international databases. Loss databases are essential to assess policy and monitor progress, but they are hardly ever mandated by national or supra‑national legislation. There are several supra-national framework directives, but they remain vague when it comes to recording losses from disasters; their implementation would hugely benefit from the availability of such information.

No single database offers complete coverage of losses from disaster events. This year’s report uses the Swiss Re database on natural catastrophes – an extensive resource that is critical for understanding the impacts and trends associated with such events. It includes detailed data on floods, storms, earthquakes, droughts, forest fires, heat waves, cold waves, frost, hail, tsunamis and other natural catastrophes. For the purposes of this report, focus is given to natural catastrophes linked to climate change; therefore, earthquakes are excluded from the analysis.

Chapter 3

The Climate Actions and Policies Measurement Framework (CAPMF) is an internationally harmonised climate policy database developed by the OECD. It is based on a structured policy typology that tracks a common set of policies with common definitions and harmonised policy attributes on an annual basis.

The 2025 edition significantly enhanced the scope, covering 87 policies across 97 jurisdictions (96 countries and the EU-27 as a bloc) from 1990 to 2024, up from 56 policies across 51 jurisdictions in earlier editions (Figure ‎B.1). The 97 jurisdictions account for around 81% of global GHG emissions including LULUCF. It covers all OECD countries except the United States, all G20 countries and all countries that account for more than 1% of global GHG emissions. The United States has chosen to not include their data in the CAPMF given concerns that the CAPMF does not fully or accurately capture U.S. climate action.

The geographical additions to the CAPMF comprise of countries in the Americas (Grenada, Honduras, Paraguay, Saint Lucia, Saint Vincent and the Grenadines), Middle East and North Africa (Egypt, Iran, Morocco, United Arab Emirates), Asia (Azerbaijan, Brunei, Cambodia, Lao PDR, Malaysia, Myanmar, Pakistan, Philippines, Singapore, Timor-Leste, Viet Nam), Sub-Saharan Africa (Angola, Benin, Botswana, Burkina Faso, Cabo Verde, Cameroon, Cote d'Ivoire, Ethiopia, Ghana, Guinea, Guinea-Bissau, Kenya, Liberia, Mali, Mozambique, Niger, Nigeria, Rwanda, Senegal, Sierra Leone, The Gambia, Togo, Uganda, United Republic of Tanzania, Zambia). Data are drawn from international sources (OECD, IEA, ITF, World Bank) and complemented by partner organisations such as the OECD Sahel and West Africa Club, the World Bank and the Global Green Growth Institute (GGGI).

The 87 climate actions and policies cover around 90% of policies listed in the latest IPCC report (IPCC, 2022[9]). For each policy, the CAPMF measures policy stringency, defined as the degree to which policies incentivise emissions reductions. The CAPMF comprises climate-positive instruments (e.g. carbon taxes), as well as reform of climate-negative measures (e.g. reform of fossil fuel subsidies). The CAPMF also includes some climate-relevant policies such as air pollution standards, i.e. policies whose primary intent is not mitigation, but which have a material effect on emissions. While the focus of the CAPMF is on national climate action, it also includes key subnational policies such as sub-national emissions trading schemes, fuel excise taxes and renewable portfolio standards, which are key in some countries.

For The Climate Action Monitor 2025 missing policy data in 2024 were substituted by the last observed data in the last five years. This concerns 18% (16 of 87) of the policies captured by the CAPMF. Substituting the imputed data by the actual data once they become available is unlikely to change the key results of Chapter 3. However, some messages may need to be refined, notably as country-level data on fossil fuel subsidies are not yet included.

Despite the enhanced scope, the CAPMF still has some limitations. Since it does not yet cover all countries or all policies, the results should be interpreted carefully. In particular, the results should be interpreted in a descriptive rather than a prescriptive way. The primary focus of the CAPMF is to track the evolution and stringency of mitigation policies over time (1990 to 2024), not to rank government’s climate action across countries. Other caveats are discussed in detail in the underlying working paper (Nachtigall et al., 2022[10]). Nevertheless, it remains a unique database offering insights into increasingly complex and diverse climate policy approaches and trends worldwide.

Figure B.1. The policy scope of the CAPMF 2025 edition

Source: Authors based on (Nachtigall et al., 2022[10]) and (Nachtigall et al., forthcoming).

References

[1] Cárdenas Rodríguez, M. et al. (2024), “National greenhouse gas emission inventories, filling the gaps in official data”, OECD Environment Working Papers, No. 252, OECD Publishing, Paris, https://doi.org/10.1787/f19f1663-en.

[3] Forster, P. (2021), “The Earth’s Energy Budget, Climate Feedbacks and Climate Sensitivity”, in Climate Change 2021 – The Physical Science Basis, Cambridge University Press, https://doi.org/10.1017/9781009157896.009.

[4] Friedlingstein, P. et al. (2025), “Global Carbon Budget 2024”, Earth System Science Data, Vol. 17/3, pp. 965-1039, https://doi.org/10.5194/essd-17-965-2025.

[2] Gütschow, J., D. Busch and M. Pflüger (2024), Gütschow, J.; Busch, D.; Pflüger, M. (2024): The PRIMAP-hist national historical emissions time series v2.6.1 (1750-2023). zenodo. doi:10.5281/zenodo.15016289.

[9] IPCC (ed.) (2022), Climate Change 2022 - Mitigation of Climate Change, Cambridge University Press, https://doi.org/10.1017/9781009157926.

[7] Maes, M. et al. (2022), “Monitoring exposure to climate-related hazards: Indicator methodology and key results”, OECD Environment Working Papers, No. 201, OECD Publishing, Paris, https://doi.org/10.1787/da074cb6-en.

[8] Maes, M. et al. (2025), “Monitoring exposure to future climate-related hazards: Forward-looking indicator results and methods using climate scenarios”, OECD Environment Working Papers, No. 264, OECD Publishing, Paris, https://doi.org/10.1787/b9ba6ee0-en.

[10] Nachtigall, D. et al. (2022), “The climate actions and policies measurement framework: A structured and harmonised climate policy database to monitor countries’ mitigation action”, OECD Environment Working Papers, No. 203, OECD Publishing, Paris, https://doi.org/10.1787/2caa60ce-en.

[6] Pizarro, R. et al. (2024), “GHG Emission Trends and Targets (GETT): Harmonised quantification methodology and indicators”, OECD Environment Working Papers, No. 230, OECD Publishing, Paris, https://doi.org/10.1787/decef216-en.

[5] UNEP (2024), Emissions Gap Report 2024: No more hot air … please! With a massive gap between rhetoric and reality, countries draft new climate commitments, United Nations Environment Programme, https://doi.org/10.59117/20.500.11822/46404.