BTR synthesis reports are prepared in response to the request from the Conference of the Parties serving as the meeting of the Parties to the Paris Agreement (CMA) at its first session for the secretariat to produce synthesis reports on BTRs and national inventory reports (NIRs) (decision 18/CMA.1, para. 6(a)).

The updated assessment covers 110 Parties, which together represent approximately 85 per cent of global GHG emissions in 2020 (see figure 1). The number includes the European Union (EU) but excludes its 27 member States, as the EU and its member States have a joint NDC target. For 23 Parties, progress towards targets could not be assessed owing to missing or inconsistent information on indicators, reference points and baselines.

Sixty-one Parties for which assessment was feasible to conduct have made progress in this initial period of NDC implementation (see figure 2), moving closer to their targets by, for example, reducing emissions, keeping emissions below a baseline scenario, using an emission budget proportionally or increasing the share of renewables in energy consumption. Together, they represent 66.2 per cent of global GHG emissions in 2020.

Twenty-seven Parties either moved temporarily further from their targets, for example by increasing emissions or using an emission budget disproportionately, or, having multiple NDC targets, showed mixed progress, with some indicators on track, some needing additional efforts and some not feasible or too early to assess.

Figure 1. Progress towards nationally determined contributions, by target type

资料来源: UN Climate Change

Figure 2. Overall progress towards nationally determined contributions, by number of Parties

资料来源: UN Climate Change

Climate policies aligned with the Paris Agreement are key to achieving NDC targets and enabling the transition to low-emission development. Parties reported nearly 5,800 policies and measures (PaMs) and actions, covering all gases and sectors, that they have planned, adopted or implemented to meet their NDC targets. Most were implemented after 2020 (figure 3), and 27 per cent of all reported PaMs are recently adopted or planned to enhance mitigation efforts towards Parties’ NDC targets and, in turn, the goals of the Paris Agreement.

Figure 3. Policies and measures reported, by implementation status

资料来源: UN Climate Change

While the energy sector remains the mainstay of Parties’ mitigation PaMs, several have stepped up efforts in the agriculture and waste sectors, including through policies with higher abatement costs than before (see figure 4).

Figure 4. Share of planned and implemented policies and measures, by sector

资料来源: UN Climate Change

Most reported PaMs target the energy sector, prioritizing the transition to cleaner sources by electrifying transport, industry and building heating, increasing the share of renewables in the energy mix, phasing out unabated coal, upgrading electricity grids, introducing carbon and energy taxation, and promoting a modal shift in transport, electric vehicles and emission performance standards for new passenger cars and vans (see figure 5). Many Parties are transforming, or planning to transform, their energy systems, mainly by electrifying end uses and modernizing grids to integrate more renewable energy.

Figure 5. Energy sector policies and measures reported, by type

资料来源: UN Climate Change

GHG trends are based on inventory reported by 134 Parties in their CRTs and BTRs. As quantitative data were not available for all Parties for the entire time series, data are presented for 101 Parties, representing about 80 per cent of global emissions in 2021, and only for 2005, 2020 and 2021. For these 101 Parties, total aggregate GHG emissions without land use, land-use change and forestry (LULUCF) rose by 13.5 per cent between 2005 and 2021, from 37.20 to 42.21 Gt CO₂ eq (see figure 6). Drivers included increased economic activity, particularly following the COVID-19 pandemic, population growth, rising energy demand and expansion of industrial and agricultural activities.

Figure 6. Total greenhouse gas emissions in 2005, 2020 and 2021 for 101 Parties

资料来源: UN Climate Change

Emissions for 134 Parties rose by 3.7 per cent (without LULUCF) between 2020 and 2021 (see figure 7), primarily owing to a post-pandemic surge in economic activity, driven largely by domestic transport and power generation.

Figure 7. Total greenhouse gas emissions in 2020 and 2021 for 134 Parties

资料来源: UN Climate Change

For the 101 Parties, the energy sector remained the largest source of GHG emissions in all reported years (2005, 2020 and 2021) and recorded the largest absolute increase between 2005 and 2021: 4.2 Gt CO₂ eq (15.9 per cent). Agriculture was the second largest source in 2005, but the industrial processes and product use (IPPU) sector overtook it in 2020 and 2021, largely owing to increased industrial activity, in particular after the pandemic, and a significant decrease in emissions for the agriculture sector (see figure 8). The IPPU sector saw the largest relative increase between 2005 and 2021, at 59.7 per cent. Net removals from LULUCF grew by 47.0 per cent in 2005–2021 (from 2.74 to 4.02 Gt CO₂ eq), primarily owing to reduced land clearing and the implementation of deforestation control plans. However, net removals fell by 5.6 per cent between 2020 and 2021 owing to factors such as soil carbon decay and the ageing of forests.

Figure 8. Total greenhouse gas emissions in 2005, 2020 and 2021 for 101 Parties, by sector

资料来源: UN Climate Change

The BTR1s provide limited data on GHG projections to 2030 and 2035. Only 59 Parties, including the EU and 27 of its member States, reported projections, representing 32.8 per cent of global GHG emissions in 2020. Several developing country Parties applied flexibility in reporting projections owing to capacity constraints.

The synthesis of GHG projections for 2030, based on submissions from 36 Parties and including projections reported by the EU for its member States, indicates that current and planned mitigation actions are projected to lead to a decrease in aggregate emissions. Parties reported projections under two main scenarios: “with measures” (WM) and “with additional measures’’ (WAM).

Under the WM scenario, which includes the effect of adopted and implemented PaMs, aggregate GHG emissions (excluding LULUCF) are projected to be 7.9 per cent below 2020 levels by 2030 (see figure 9). Under the WAM scenario, which also includes planned PaMs, emissions fall further to 12.2 per cent below 2020 levels. Implementing planned PaMs would thus cut emissions by an additional 715.8 Mt CO₂ eq in 2030 compared with the WM scenario.

Figure 9. Historical and projected greenhouse gas emissions without land use, land-use change and forestry under the ‘with measures’ and ‘with additional measures’ scenarios

资料来源: UN Climate Change

Under the WM scenario, the energy sector (excluding transport) is projected to achieve the largest reduction in emissions by 2030, at 31.9 per cent compared with 2020 levels (see figure 10). The energy sector (including transport) is expected to remain the dominant source, contributing 76.2 per cent of total emissions without LULUCF in 2030. Despite overall reductions, emissions from the IPPU and agriculture sectors are projected to increase by 0.3 and 1.7 per cent, respectively, compared with 2020 levels. Waste sector emissions are projected to remain roughly unchanged, while net removals from the LULUCF sector are expected to fall by 6.9 per cent.

Figure 10. Historical and projected greenhouse gas emissions and removals under the ‘with measures’ scenario, by sector

资料来源: UN Climate Change

Adaptation is a central focus of the BTRs. Although reporting on it is not mandatory, 92 per cent of Parties included an adaptation component.

Parties consistently reported climate trends and impacts, particularly rising temperatures, droughts, flooding and changing precipitation. Food and agriculture, ecosystems and biodiversity, infrastructure and human settlements, water and sanitation, and health were among the most vulnerable and highest-priority sectors (see figure 11).

Figure 11. Share of adaptation components of biennial transparency reports covering climate change hazards and their impacts on priority sectors and areas, in the order of the thematic targets under the United Arab Emirates Framework for Global Climate Resilience

资料来源: UN Climate Change

Note: The numbers in parentheses refer to the thematic targets under the United Arab Emirates Framework for Global Climate Resilience set out in decision 2/CMA.5, para. 9.

Almost all (97 per cent) Parties reported on their domestic adaptation priorities, covering a wide range of sectoral, cross-sectoral and institutional areas. Food and agriculture, and water and sanitation, were the highest-priority sectors. Almost all Parties (93 per cent) also reported progress in implementing adaptation across sectors and areas, showing broad but incomplete alignment between priorities and implementation.

Nearly half of all Parties described how the United Arab Emirates Framework for Global Climate Resilience guides their adaptation actions, and one quarter of them explicitly linked their implemented adaptation measures to the thematic and dimensional targets (see figure 12).

Figure 12. Shares of adaptation components of biennial transparency reports referring to specific adaptation priorities in sectors and areas, progress made in implementing adaptation, and the explicit reference between implemented adaptation measures and the targets under the United Arab Emirates Framework for Global Climate Resilience

资料来源: UN Climate Change

Note: The numbers in parentheses refer to the thematic and dimensional targets under the United Arab Emirates Framework for Global Climate Resilience set out in decision 2/CMA.5, paras. 9 and 10.

Of the 137 BTR1s synthesized, 88 report on loss and damage. The scope and depth of reporting vary considerably: about half provide one page or less of information, while six devote more than 10 pages. Some Parties refer readers to adaptation chapters or national adaptation plans rather than providing dedicated content. A total of 82 Parties described activities to avert, minimize or address loss and damage, while 51 reported specific losses. In the absence of standardized methodologies and reporting guidance, Parties used varied approaches and framings, limiting comparability and synthesis.

 Among the 51 Parties that reported specific losses, economic loss, loss of agricultural production and loss of life account for 63 per cent of the 419 losses reported across 16 categories (see figure 13). Economic loss, including generic references to the term, is the most frequently reported category (34.6 per cent), appearing in 46 BTR1s. Monetary values accompany 92 per cent of economic loss entries, indicating a tendency to report losses that can be tracked financially. Breadth varies: the median Party reported four loss categories, 10 reported only one and 24 reported five or more. Floods, storms and droughts are the hazards most often associated with reported losses.

Figure 13. Loss associated with climate change impacts reported, by type

资料来源: UN Climate Change

Parties reported more than 600 activities, actions, measures, systems, frameworks, policies, initiatives and plans related to loss and damage. Of these reported activities, only 22 per cent were described in terms of “averting, minimizing and addressing” loss and damage. The most widely reported activities are policy and planning frameworks, early warning systems, risk analysis and assessment, climate-resilient infrastructure and emergency crisis management. Reported actions span pre-emptive activities, contingency arrangements and actions to manage impacts; pre-emptive activities are reported most often and actions to manage impacts least often (see figure 14).

An analysis of 18 new BTR1s that contain information on loss and damage, submitted since the first synthesis in 2025, shows emerging shifts in reporting practices: the use of the “averting, minimizing and addressing” framing is more prevalent in these BTRs, appearing in 39 per cent of the submissions, compared with 16 per cent of the BTRs covered by the 2025 synthesis (the previous cohort). However, the small sample, which included several small island developing States and coastal States, makes it premature to call these established trends.

These new BTR1s report activity types more widely than the previous cohort. Regional and international collaboration features in 44 per cent of submissions, compared with 6 per cent of the previous cohort. Emergency crisis management, climate-resilient infrastructure, coastal management and flood defence, and agricultural strengthening are also reported by a substantially higher proportion of Parties in the new BTR1s, while contingency arrangements account for 28 per cent of reported activities, compared with 18 per cent in the previous cohort.

Institutional arrangements are also more visible: 65 per cent of reported activities in the new BTR1s are linked to an identifiable arrangement, compared with 49 per cent in the BTRs analysed in the previous cohort.

Figure 14. Activities related to averting, minimizing and addressing loss and damage reported, by type

资料来源: UN Climate Change

The BTR1s show an increase in financial, technology and capacity-building support provided to developing countries for climate action in the 2021–2022 biennium.

Financial support

Reported annual average climate finance, primarily from developed country Parties, largely aligns with recipient countries’ priorities, flowing mainly to energy and transport for mitigation and to agriculture and food supply for adaptation (see figure 15). A gap remains for multi-sectoral adaptation needs.

Figure 15. Financial support reported as provided and mobilized, and needed and received, by thematic area

资料来源: UN Climate Change

The annual average climate-specific finance provided and mobilized by 41 Parties reached USD 65.16 billion in 2021–2022, including finance provided through bilateral, regional and other channels, climate-specific multilateral finance and climate finance mobilized through public interventions (see figure 16). The 41 Parties include all Parties that reported finance provided or mobilized under any of these categories in either reporting year. Developed country Parties provided or mobilized 97.1 per cent of the total. Most support took the form of grants and concessional instruments.

Figure 16. Financial support reported as provided through bilateral, regional and other channels, multilateral channels and mobilized through public interventions in 2021–2022

资料来源: UN Climate Change

A total of 40 Parties reported detailed information on financial support provided through bilateral, regional and other channels, either in a separate file or in the text of the BTR. This support averaged USD 40.79 billion annually in 2021–2022.

Thirty-five Parties reported financial support provided through multilateral channels in at least one of the two reporting years, with annual averages in 2021–2022 of USD 10.19 billion for climate-specific purposes and USD 11.33 billion for core/general purposes (see figure 17).

A total of 51 developing country Parties reported needing nearly USD 6.9 trillion for climate action (mostly before 2030). In addition, 77 Parties reported receiving USD 91.19 billion in financial support, either in a separate file or in the text of the BTR. Many developing countries are still establishing systems for collecting and tracking information on support received, so not all could report on support received or needed in their BTRs.

Figure 17. Total financial support reported as provided through multilateral channels in 2021–2022, by entity

资料来源: UN Climate Change

Technology development and transfer support

Information on technology development and transfer support appears in 92 per cent of BTR1s, covering 3,410 reported activities or measures (see figure 18). Sectoral priorities for technology support broadly align with those in the latest NDCs, and mitigation-related support is reported by more Parties than adaptation-related support (see figure 19). Reported measures and activities focused mainly on hardware and infrastructure for climate technology development and transfer, and on institutional strengthening. A total of 31 Parties indicated that their identified needs for technology development and transfer support were informed by technology needs assessments (TNAs), while 12 reported a need to update, complete or undertake the TNA process. Bilateral channels accounted for 80 per cent of reported support provided, and support received went primarily to public-sector entities. Private-sector involvement as a recipient remained limited, although 50 per cent of Parties reporting support provided highlighted the private sector’s role in advancing technology development and transfer.

Figure 18. Regional distribution of the reported information on activities and measures relating to technology development and transfer support provided, needed and received in BTR1s, by activity

资料来源: UN Climate Change

Figure 19. Parties that reported information on technology development and transfer support provided, needed and received across activities focused on mitigation, adaptation and cross-cutting issues in BTR1s, by Party

资料来源: UN Climate Change

Capacity-building support

Information on capacity-building support appears in 82.6 per cent of BTR1s: 42 Parties reported support provided, 75 reported support received, including three that reported both. A total of 8,563 capacity-building activities were reported as support provided, focusing primarily on adaptation (61.1 per cent), followed by cross-cutting areas (20.7 per cent) and mitigation (18.2 per cent). Africa (31.7 per cent), Asia and the Pacific (21.7 per cent) and Latin America and the Caribbean (15.6 per cent) were the main destinations of this support, of which 54.1 per cent of activities were completed and 43.8 per cent were ongoing. A total of 69 Parties reported 1,850 capacity-building needs, mainly related to adaptation (39.5 per cent), mitigation (30.2 per cent) and cross-cutting areas (22.5 per cent), including institutional readiness, climate finance, technology deployment, transparency systems, loss and damage, and carbon markets. A further 53 Parties reported transparency-related needs. Seventy-five Parties reported capacity-building support received, covering 2,405 activities across adaptation (29.4 per cent), mitigation (26.3 per cent) and cross-cutting areas (25.7 per cent); 18.6 per cent of activities were not classified. Latin America and the Caribbean reported the largest number of activities received (822), followed by Asia and the Pacific (652) and Africa (525) (see figure 20). Support commonly focused on technical training, institutional strengthening, climate finance readiness, renewable energy and ETF-related transparency capacities, including preparation of BTRs and NIRs, GHG inventory systems and quality assurance and quality control.

Figure 20. Capacity-building activities received, by region and area

资料来源: UN Climate Change

The BTR1s show a strong commitment by Parties to a whole-of-society approach to climate action, recognizing it as a collective effort that extends far beyond government. This involves engaging a wide array of non-Party stakeholders, including the private sector, civil society and local communities, and integrating diverse perspectives, such as those of women, youth and Indigenous Peoples, to make climate policy more inclusive, effective and representative. The approach also fosters synergies between climate action and the Sustainable Development Goals (SDGs) by embedding climate policies in national development plans to maximize socioeconomic co-benefits and a just transition (see figure 21).

Most Parties (about 80 per cent) reported involving a broad spectrum of non-Party stakeholders, including the private sector, civil society organizations, academic and research institutions, local communities and international organizations, in preparing climate-related reports (e.g. BTRs) and in policy development and implementation, through targeted stakeholder consultations, public discussions and initiatives, and multi-stakeholder councils and thematic working groups that support inclusive, representative and effective climate action.

Parties are working to integrate the needs and contributions of marginalized groups: nearly 76 per cent explicitly considered gender in their climate action and over half engaged and empowered youth. Parties with Indigenous populations recognize and integrate Indigenous Peoples’ traditional knowledge in national climate change policies and strategies.

Nearly all Parties (92 per cent) explicitly link climate action with broader sustainable development goals – such as those related to clean energy, sustainable cities and communities, sustainable production and consumption, green growth, high quality of life and a socially inclusive transition – by embedding climate targets and resilience goals in their long-term national development plans.

Figure 21. Percentage of Parties reporting on a whole-of-society approach

资料来源: UN Climate Change

The synthesis of 137 BTR1s indicates that Parties are working to establish robust domestic transparency arrangements – including legal frameworks, institutional coordination and centralized data systems – to meet the enhanced requirements of the ETF. Despite these efforts, many developing countries face significant institutional, technical, data quality and human resource constraints, and so apply flexibility provisions to fulfil their reporting obligations.

Of the 96 developing country Parties considered among the 137 Parties, 74 applied at least one of the 12 flexibility provisions in the modalities, procedures and guidelines (see figure 22), primarily owing to data availability-related and technical constraints (e.g. reliance on lower-tier methodologies of the Intergovernmental Panel on Climate Change (IPCC) owing to a lack of country-specific data, and insufficient domestic systems for tracking finance received) and institutional constraints (e.g. weak inter-agency coordination and unclear data-sharing mandates).

Figure 22. Flexibilities applied by developing country Parties, by reporting requirement

资料来源: UN Climate Change

Sixty-nine developing country Parties articulated clear capacity-building needs in their BTRs and 52 outlined improvement plans for future reporting cycles (see figure 23). Capacity-building needs were mostly identified for applying higher-tier IPCC methodologies, developing country-specific emission factors, using tracking and accounting tools to monitor NDC implementation and target achievement, creating robust monitoring and evaluation systems for adaptation, and establishing better systems for tracking financial and technological support.

Figure 23. Capacity constraints reported, by type of constraint

资料来源: UN Climate Change