The impacts of climate change on natural disasters are intensifying, giving rise to new characteristics and trends in disaster activities, and a significant increase in disaster risks. Disaster prevention and mitigation efforts now face unprecedented challenges. This paper examines the mechanisms and activity patterns of natural disasters under climate-driven factors, focusing on cross-sphere disaster characteristics and the spatiotemporal ocean-land linkages of disaster activities. It highlights the “new normal” and challenges of disaster risks in the context of climate change and evaluates the effectiveness and limitations of current disaster risk management strategies. To enhance the scientific and technological capabilities for disaster risk prevention, this paper proposes five key scientific questions: (1) The impacts of climate change on sphere processes and their disaster-inducing mechanisms; (2) Prediction and risk evolution of catastrophic events driven by extreme weather; (3) Mechanisms and risk assessments of major disasters on socio-economic systems; (4) AI-driven adaptive framework for dynamic disaster risk management; (5) Theoretical frameworks for building resilient societies to adapt to climate change.

Integrated Assessment Models (IAMs) have played a significant role in the global and national processes of addressing climate change, especially in all the assessment reports of the Intergovernmental Panel on Climate Change (IPCC), supporting the evaluation and formulation of global emission reduction targets. The development of IAMs themselves has gone through stages from highly synthesized models to large-scale complex models. With the CO₂ emissions of countries committed to carbon neutrality accounting for the majority of global CO₂ emissions, the research direction of IAMs also needs to undergo major adjustments, shifting from the original focus on assessing scenarios and pathways for temperature targets to more detailed studies of economic sectors, technologies, and related economic and ecological environmental factors, in order to support the understanding and formulation of the paths and policy measures for energy and economic transitions under the goal of carbon neutrality. The transition of IAMs research needs to be advanced as soon as possible and requires the participation of more academic research groups.

In presence of anthropogenic forcing, global climate has exhibited a long-term warming trend, superimposed by a quasi-periodic multidecadal oscillation of 60—70 years, which is strongly influenced by the Atlantic Meridional Overturning Circulation (AMOC). As a critical component of the global ocean circulation, AMOC governs the distribution of ocean heat and freshwater, thereby significantly impacting climate. This paper reviews the structure and variability of AMOC based on direct observation array and the observation proxy since the instrumental temperature, salinity and sea surface height are available. We show that the AMOC leads the global mean surface temperature by approximately 45°—90°, which is primarily driven by heat transport in the intermediate and deep ocean and its effect on the surface climate system’s energy balance modulated by external radiative forcing. We also address key challenges in understanding AMOC variability and its climatic implications: first, observations did not exhibit statistically significant AMOC trend, providing few supports to the AMOC slowdown shown in numerical models; second, external radiative forcing may alter the relationship between AMOC variability and global surface temperature through its impacts on the internal climate variability. Future research should focus on continuous, high-quality observations to enhance understanding of AMOC’s multidecadal variability and its climate impacts, for more accurate climate models and more effective climate change policies.

In February 2025, the 62nd session of the United Nations Intergovernmental Panel on Climate Change (IPCC) approved the chapter outline of the Working Group I (WGI) contribution to the IPCC Seventh Assessment Report (AR7), laying the foundation for the subsequent drafting of AR7. The main report includes four sections: framework overview, current status and trends, future changes, and information supporting adaptation, organized into ten chapters. This paper briefly introduces the key content and assessments in three major areas of focus for AR7 WGI: “Current Status and Trends” (Chapters 2-4) assesses large-scale climate system changes, regional climate extremes, and advances in Earth system processes (e.g., biogeochemical cycles, energy/water fluxes); “Future Changes” (Chapters 5-8) introduces first-ever standalone chapters on emission scenarios/global temperature projections and Earth system tipping points, alongside global/regional climate projections; “Information Supporting Adaptation” (Chapters 9-10) evaluates Earth system responses under net-zero/overshoot pathways and integrates climate services with Indigenous knowledge for policy applications. Compared to the Sixth Assessment Report (AR6), the AR7 WGI chapter outline presents three new features: (1) a significant reduction in length, especially regarding the understanding of Earth system processes through consolidating AR6’s five process-oriented chapters into one unified chapter (Chapter 4) to spotlight post-AR6 breakthroughs; (2) a heightened focus on the relationship between emission scenarios and future global warming, Earth system tipping points, low probability-high impact events, and critical thresholds; and (3) a stronger emphasis on evaluating information to support adaptation, including the assessment of Earth system responses to climate interventions (including overshoot pathways) and cross-WG coordination. Based on insights from the WGI chapter outline, this paper discusses five critical research areas that need strengthening in China: developing future emission scenarios independent of the current Western narratives, innovating methodologies and data by using km-scale storm-resolving models and AI in regional climate change research, accelerating Earth system model development with full carbon cycle representation for emission-driven climate projections, deepening foundational research on climate stability, reversibility, and tipping points, as well as assessing impact of climate interventions.

In early March 2025, the 62nd plenary session of the United Nations Intergovernmental Panel on Climate Change (IPCC) considered, adopted and released the outline of the report of Working Group II (WGII) of the Seventh Assessment Report (AR7), which provides a scientific basis and action guidelines for the next step in the preparation of the AR7. The outline clearly sets out the four major topics of summary, global assessment, regional assessment and thematic assessment in a total of 20 chapters. In addition, it is planned to update the IPCC Technical Guidelines for Assessing Impacts of and Adaptation to Climate Change (1994) and add new content on adaptation tools, modules and drivers. WGII aims to provide a more comprehensive scientific assessment of climate change impacts, adaptation and vulnerability, as well as the latest research progress through systematic risk analysis, inclusive framework design and methodological innovations, and it will provide a scientific basis for global climate policies and actions. This article briefly describes the contents and key points of the global assessment, regional assessment and thematic assessment areas of concern in AR7 WGII. Compared with the Sixth Assessment Report (AR6), the AR7 WGII presents three new features in its overall structure: (1) The global assessment will be placed before the thematic (sectoral and domain) assessments, and the integrated analysis of cross-scale risks will be strengthened; (2) The assessment of the effectiveness of adaptation measures will be emphasized; (3) New chapters will be added on response to loss and damage, as well as finance. Based on the outline of the WGII report, key research points and important insights are proposed in various areas such as global and regional scales, water resources, agricultural development, public health and livelihoods security, etc., which provide a scientific framework for future research on climate change impacts, adaptation and vulnerability, and are of great significance in promoting climate change response measures and realizing the sustainable development goals on a global scale.

As climate change intensifies, developing a systematic and forward-looking framework for climate mitigation assessment has become a critical issue in global governance. Building upon the foundations of the Sixth Assessment Report (AR6), the Working Group III (WGIII) of the Intergovernmental Panel on Climate Change (IPCC) has undertaken a comprehensive restructuring of its Seventh Assessment Report (AR7), focusing on improving policy relevance, governance dimensions, and technological pathways. Notable advancements in AR7 include the introduction of ex-post policy assessment, enhancing cross-sectoral integration, expanding analysis of green finance, increasing attention to demand-side strategies and social equity, and the establishment of dedicated chapters on carbon dioxide removal (CDR) and ocean-based mitigation. This paper reviews the development and structure of the AR7 WGIII framework, summarizes the key contributions and limitations of AR6, and analyzes the major areas of refinement in AR7. Drawing on China’s ongoing climate policy practices, the paper proposes targeted recommendations such as strengthening policy evaluation, breaking sectoral silos, deepening green finance reform, advancing demand-side mitigation, and accelerating CDR deployment. It further calls for enhanced research in critical frontier areas to better support future IPCC assessments and elevate China’s knowledge contribution and influence within the global climate governance architecture.

Climate change has amplified the range, frequency, and intensity of extreme weather events, leading to substantial economic losses. While existing attribution studies have quantified the role of anthropogenic climate change in increasing the probability of such events, its contribution to the resulting economic losses remains poorly understood. This knowledge gap hinders the development of effective adaptation policies. Based on the latest advances in extreme event attribution research, a multi-regional input-output model was employed to evaluate both direct and indirect economic losses from extreme events across China’s provinces. The portion of these losses attributable to climate change was quantified and key adaptation priorities were identified by sector and region. Findings indicate that extreme events attributed to anthropogenic climate change result in average annual direct and indirect losses of approximately CNY 80 billion and CNY 91 billion yuan, respectively, accounting for around 27% of disaster-related losses. The manufacturing and agriculture sectors are identified as the most affected, while industries such as finance, real estate, wholesale and retail, and business services, though not directly impacted, also incur significant losses.

South China is located at the northern edge of the world’s largest mangrove distribution area, and more than 90% of China’s mangroves are distributed in this area. Global warming and continued sea level rise pose a major threat to the land use and economic and social sustainable development of coastal areas characterized by mangroves in South China. By integrating historical sea level data, projections from multiple climate models (CMIP6) under different SSPs scenarios, and detailed land use data related to mangroves, this paper explores the trend of sea level change and its inundation risk under low emission (SSP1-2.6), medium emission (SSP2-4.5) and high emission (SSP5-8.5) scenarios. The key findings are as follows. (1) From 1995 to 2022, the sea level in the coastal areas of South China continued to rise, with an average rising rate of 3.96 mm/a, which is higher than the global average sea level rise rate of about 3.3 mm/a during the same period. It is expected that the average sea level in South China will continue to rise in the 21st century. Under different scenarios, the final period (2080-2100) will see a rise of 0.46 [0.31-0.58] m, 0.54 [0.36-0.71] m and 0.72 [0.55-0.89] m respectively compared with the baseline period (1995-2014). (2) Under the three scenarios at the end of the 21st century, about 235000-368000 hm² of coastal zone will be submerged due to sea level rise. The areas with more serious submergence are mainly concentrated in the Pearl River delta, northeastern Hainan and southeastern Guangxi. (3) If land use remains the same as in 2020, among all land types, construction land will experience the largest inundation area (48200-71600 hm²); The proportion of mangrove forests flooded is very high (9900 to 14300 hm²), accounting for 39% to 57% of their total area. The research results can provide a scientific basis for formulating targeted mangrove protection strategies and integrated coastal management plans, so as to achieve the multiple goals of protecting the ecological functions of mangroves, ensuring regional ecological security, and promoting sustainable economic and social development.

Through the trend analysis of China’s transition from “dual control” of energy consumption to “dual control” of carbon emissions, three challenges in the transition are identified including mechanism coordination, target decomposition and basic conditions, and domestic and international experiences of decomposition of carbon emission control targets are sorted out. In China’s “15th Five-Year Plan”, it is more suitable to adopt the national carbon intensity control target. From six perspectives of fairness, transparency, cost effectiveness, data availability, coordination difficulty, and target completion risk, three approaches and implementation plans are put forward and compared for regional decomposition of carbon emission control targets during the “15th Five-Year Plan” period. The first approach is to set target for each province separately from top to down, continuing the experiences during the 13th Five-Year Plan and the 14th Five-Year Plan periods. The second approach is to develop a “two up and two down” national-regional iterative communication target setting mechanism based on the local determined targets. The third approach is to set a cap for the national carbon market and decomposed provincial targets for non-carbon markets. Based on comparison, it is recommended to adopt the second one currently. Relevant policy suggestions are put forward at last.

Achieving carbon neutrality is an important strategy for China to coordinate its socioeconomic development with the construction of ecological civilization. Accurately grasping the spatial and temporal characteristics of carbon source/sink balance across provinces is of great significance for policy making to achieve the carbon peaking and carbon neutrality goals. Based on the Carbon Emission Accounts and Datasets (CEADs) and land use data, the spatiotemporal characteristics of provincial carbon emissions and sinks in China were analyzed over a long period of time from 2000 to 2020. The carbon balance status of each province was evaluated based on the Economic Coordinated Development Index, and the impact analysis of multiple socio-economic factors was explored. The results showed that: (1) China’s total carbon emissions increased from 3.05 billion tons to 10.97 billion tons, with 19 provinces experiencing a continuous increase in carbon emissions, and 10 provinces fell after an increase. The overall spatial characteristics of carbon emissions shifted from high in the east and low in the west to high in the north and low in the south. (2) The total amount of carbon sinks in China followed a raise-fall-raise pattern. The total carbon sinks of China fell slightly from 1.261 billion tons to 1.260 billion tons, with most provinces reporting slight changes. The inter-provincial pattern featured high in the west and low in the east, with high carbon sink in the southwest and northeast, followed by the southeast, while the Northwest and East China registered the lowest. (3) The provincial government experienced carbon budget deficit. The deficit was on the rise, but the growth rate was tightening. In terms of the performance of Carbon Eco-Security Index and Ecological Economic Coordination Index, 11 provinces including Shanghai and Tianjin were high in the former and low in the latter, 9 provinces including Liaoning and Shaanxi exhibited the same performance, while 10 provinces including Jilin and Heilongjiang were low in the former and high in the latter. (4) The contribution of urbanization ratio to the Ecological Economic Coordination Index was positive and showed an upward trend over time, with a spatial pattern of higher in the northwest and lower in the southeast. The contribution of total population, regional gross domestic product, added value of secondary industry, and coal consumption were generally negative. The contribution of the number of patent application authorization was generally not significant, but positive, and the spatial difference was not significant.

Carbon trading market is the key policy tool to promote global climate governance and accelerate the progress of carbon peaking and carbon neutrality. The carbon trading activities in different sectors, such as energy, construction, forestry and agriculture, need the support of meteorological services. The construction of China’s carbon market has achieved preliminary success, but problems exist, e.g., simple trading subject and product, insufficient market vitality, and inadequate market functions. The construction of carbon market urgently needs to improve meteorological service guarantee from both supply and demand sides. On the basis of development trend of global carbon market, this paper analyzes the demand, current situation and existing problems of carbon market construction for meteorological service guarantee. Countermeasures and suggestions are proposed for further improving the meteorological service support capacity from multiple aspects, i.e., stepping up institutional building, expanding service scope, promoting carbon financial service, broadening international cooperation and strengthening personnel training. This study can provide references for high-quality service guarantee of carbon market construction, contributing to expand the application scenario of “meteorology×finance” for meteorological departments.

This paper reviews and analyzes the evolution of country classification in United Nation Framework of Climate Change Convention (UNFCCC) system and other multilateral organizations.
In UNFCCC, parties were classified by Annex I (including developed country parties and economies in transition) and non-Annex I, which was further enhanced in Kyoto Protocol where most Annex I Parties (except Turkey and Belarus) bear quantified emission reduction and limitation targets. However, under Paris Agreement, this clear classification was shifted to the differentiation by “developed parties” and “developing parties”, which is ambiguous in term of criteria. The shift reflected the complicated impacts brought by the significant changes of global development structure and irresistible trend towards a uniform framework applicable to all Parties.
Furthermore, this shift interacted with classification methods in other multilateral mechanisms as both cause and effect. M49 standard developed by United Nation Statistic Department (UNSD) once used ‘developed and developing region’ as one of classification method to group countries, but it was canceled in 2021. Similarly, country grouping in Inter-governmental Panel of Climate Change (IPCC) system changed from using UNFCCC method generally in WGIII report of AR5, to using UNFCCC method with minor changes in underling reports of WGIII report of AR6, and finally, to pure geographic classification in SPM of the report. Stability is observed in World Bank classification method, where income is the only criteria used across the time.
By the end of March, 2025, 100 Parties of Paris Agreement submitted the first Biennial Transparent Report (BTR). According to statistics provided by UNFCCC Secretary, 66 developing countries and 34 developed countries submitted BTRs, though the approach to classify countries is not disclosed. After analyzing these 100 BTRs, it was noticed that “self-differentiation” has emerged. For example, Turkey and Russia Federation, Annex I Parties under UNFCCC, announce specifically that they fulfil the responsibility of the Agreement as developing countries, and Israel, for the first time, submitted BTR as a developed country, though it is a non-Annex I Party. And around one fifth Parties do not clearly mention their country’s attribution in term of ‘developed’ and ‘developing’.
These few cases are of typical significance. On one hand, self-differentiation makes sense, as Parris Agreement neither has its own annex, nor has hard linkage with UNFCCC annex, and, particularly, there is no dynamic adjustment mechanism for UNFCCC annex, raising widespread concerns for its mis-matching with the evolving situation; on the other hand, Paris Agreement, taking national-determined contribution as a major instrument, has already become less enforcing when compared with KP in which Annex I Parties took their legally-binding commitments by top-down approach literally; when the grouping of party goes also to the direction of self-differentiation, the Agreement will lose more force certainly. This will release negative signals to global climate governance, though there is also self-upgrading.
When we enter in an era when globalization is seriously challenged, national-determined principle tends to be used in wider situation and self-differentiation becomes possible, the economic indication contained in ‘developed’ and ‘developing’ countries is largely replaced by political perspective, losing its original content of burden-sharing and equity. In order to maintain the effectiveness of UNFCCC system, international society might have to give up the tangling with these two words, and focus on mechanisms like Enhanced Transparent Framework (ETF), Global Stocktake (GST) which have sort of top-down arrangements, fostering the establishment of climate governance based on best efforts and enhanced actions of each Party and non-state actors, in accordance with national circumstance.

Paris Agreement, adopted in 2015, has initiated the new paradigm of global climate governance. Over the past decade, with the completion of the Paris implementation rulebook, the advancement of the five-year “implementation cycle”, and the emergence of new issues such as loss and damage and just transition, the global climate governance has steadily progressed towards a direction of being “fair, reasonable, cooperative and win-win”. Amidst the dramatic shifts in the global political and economic landscape, the breaking records of global surface temperature, and the United States’ withdrawal from the Paris Agreement for the second time under President Trump, the upcoming COP30 Belém Climate Conference stands as another critical juncture in the intergovernmental climate change process. Key negotiation topics will include global goal on adaptation, mitigation, deforestation, and just transition, as well as the potential refinement on the implementation mechanism of the Paris Agreement. Upon the decennial of the Paris Agreement, reviewing its progress, analyzing key contentions and challenges, and envisioning the prospects of global climate governance, will be helpful to achieve a balanced and comprehensive outcome in Belém.

The 29th Conference of the Parties (COP29) to the United Nations Framework Convention on Climate Change (UNFCCC) adopted decisions on Article 6 of the Paris Agreement and reached a balanced package of outcomes known as the “Baku Climate Unity Pact”, including decisions on new collective quantified goal on climate finance, mitigation work programme, global goal on adaptation. COP29, a bridging conference held after the first global stocktake under the Paris Agreement and before Parties submit a new round of Nationally Determined Contributions (NDCs), has successfully concluded despite the shadow of a potential U.S. withdrawal from the Paris Agreement. The outcomes have strongly upheld multilateralism and advanced global climate governance. However, challenges remain, including follow-up arrangements on finance, mitigation, and the global stocktake, as well as the new situation of procedural developments at the conference that deviated from established multilateral negotiation rules. Additionally, the prospect of the U.S.’s “de-climatization” policies and the EU’s rightward political shift pose significant constraints on climate action. It is recommended to proactively address U.S. withdrawal from the Paris Agreement, actively guide the direction of global climate governance, leverage climate and trade issues, strengthen research on China’s climate finance mechanism, and holistically prepare for COP30 in advance.