The article proposes the main scientific issues associated with achieving carbon neutrality goal. The scientific understanding needed for achieving carbon neutrality goal and its role in supporting the achievement of this goal are comprehensively discussed focusing on three aspects of natural changes in the Earth system, the relationships between carbon neutrality and the natural Earth system, as well as between carbon neutrality and human activities. It is indicated specifically that the scientific issues related to natural changes in the Earth system include the understanding of carbon cycle in the Earth natural system, the role played by natural processes in climate warming, and paleoclimate change. The scientific issues related to the relationship between carbon neutrality and the Earth natural system include the impact of carbon neutrality on the Earth natural system, and sensitivities of climate warming to greenhouse gas radiative forcing. The scientific issues related to the relationship between carbon neutrality and human activities include interactions of the Earth natural system with socio-economic system, local-scale atmospheric variations associated with clean energy development and its impacts, as well as geoengineering and its influences on the Earth natural system. It is pointed out that an in-depth understanding of these issues will offer an essential scientific basis for adapting and mitigating climate change reasonably and effectively, which can provide an important scientific support in achieving the goal of carbon neutrality.

Climate change is a serious challenge to natural ecology and human society. As an important tool for addressing climate change, climate models provide important support for understanding the mechanism of the past climate system, climate services and projections of future global change scenarios. However, problems in process representation, subgrid parameterization and spatial resolution of climate models have severely limited their simulation and prediction capabilities. With the development of economy and society, artificial intelligence (AI) technology has been widely used, and its advantages of integrating multi-source data, identifying potential information, and learning from existing “experience” are expected to provide new assistance for climate research and application. Against this background, this paper firstly provides a concise review of the development of climate models, then combines the characteristics of AI on this basis to examine the application of AI in climate research and services, and analyzes the challenges faced at this stage. The results show that existing observational data and model outputs can provide a sufficient data base for AI applications, and AI can optimize and integrate climate models accordingly, thus improving the accuracy of climate simulation and prediction results. In the future, it is important to focus on the coupling of AI and climate models and to expand the application of AI in various areas of climate change, so as to more effectively address the challenges posed by global climate change.

Weather forecasting is closely related to the social economy and people’s lives. With the intensification of global warming, extreme weather events are widespread, frequent and intense, and traditional weather forecasting will face more significant challenges. Firstly, the relationship between climate change and extreme weather events is expounded in this paper, and then the impacts of global climate change on conventional and extreme weather forecast are analyzed, and it is found that climate change will increase the difficulty of extreme weather forecasting, and the role of improving the accuracy of extreme weather forecasting in disaster prevention and mitigation under the “new normal” is also emphasized and further analysis of climate warming will make weather forecasting face new challenges. On this basis, this paper further puts forward new trends of future weather forecast operational developments as well as countermeasures and suggestions to adapt to climate change, such as vigorously developing high-resolution and multi-circle nested numerical prediction models, in-depth research on the mechanism and predictability of extreme weather events in the context of climate change, developing the combination of dynamic-statistical model based on mechanism and big data analysis, artificial intelligence technology and new forecasting methods, and improving the scientific literacy and ability of forecasters.

The Asian Water Tower is the most important and vulnerable water tower in the world. Its most prominent feature is the glacier and snow processes. Climate change has led to a rapid reduction of solid water bodies such as glaciers and snow in the Asian Water Tower, while liquid water bodies such as lakes and rivers have significantly increased, resulting in an imbalance between solid and liquid phases. There is a spatial imbalance in the distribution of water resources, with an increase in water resources in the northern endorheic basins and a decrease in the southern exorheic basins. Glaciers are melting at an accelerated rate, with significant spatial differences between the southeast and northwest, showing severe glacial mass loss in the southeast and Tianshan regions, relatively minor losses in the northwest regions, and relative stability or advancement in the Pamir and West Kunlun regions. Snow cover and annual snow days have decreased, snowmelt is occurring earlier, and both maximum snow water equivalent and snowmelt are decreasing. In the future, research should be focused on the changes in glacier and snow processes in high-altitude areas, improving the spatiotemporal resolution of glacier and snow process models, strengthening research on future water resource changes under different scenarios, and proposing water security response strategies.

In the past 40 years, climate change has led to the warming and humidification of the Tibetan Plateau, which has had a significant impact on the geographical distribution and function of ecosystems of forests, shrubs, grasslands, wetlands, and deserts. The distribution range of shrubs, grasslands and wetlands is expanding, with the boundary moving westward and towards high-altitude areas. Under the influence of climate change, the productivity, carbon sequestration, and soil conservation capacity of the ecosystem on the Tibetan Plateau have improved, and changes in water conservation have shown significant special heterogeneity. The profound impact of climate change on phenology, plant growth rate, distribution range and species interactions of animals and plants, as well as biodiversity, requires further observation and research.

The “Beautiful Cryosphere” (BC) is the extension and application of the concept of a “Beautiful China” in the cryosphere. It is a synthesis of natural beauty, service beauty, and harmonious beauty, and a dialectical unity of benefits and harms. The concept of the BC is re-explained in the text by reviewing and re-interpreting the connotation of the BC, analyzing the relationship between the BC and “Beautiful China”. On this basis, the origin and development course of the BC are analyzed from the two main lines of the systematization of cryosphere science and the construction of a Beautiful China and its researches, from the discipline and social perspectives. The two levels of research content within the BC are further analyzed. Driven by advances in understanding, national needs, and scientific research projects over the past 20 years. The evolution of the BC research content includes three phases: an exploration stage from 2007 to 2015, the stage of expansion and summary between 2015 and 2020, and comprehensive deepening stage from 2020 to the present.

The impact of climate change on the industrial sector is gaining increasing attention. Both slow-onset and sudden climate factors have important impacts on the manufacturing, mining, and electricity industries. In the short term, the industrial sector mainly engages in passive adaptation under the influence of climate factors, while in the long term, it can engage in proactive adaptation when anticipating climate change and its potential consequences. Case studies and questionnaire surveys are important approaches to understanding and analyzing the adaptive behavior of individual enterprises, while various econometric models and integrated models still focus on assessing the impact of climate change on industrial output, exports and other aspects, lacking evaluation and analysis of the climate adaptation behavior of the industrial sector. The challenges of adapting to climate change involve both research and practice. In terms of research, the definition of climate adaptation is controversial, and there exists a lack of exploration regarding the effectiveness of adaptation, maladaptation, and adaptive limits. In practice, cost and decision-making barriers are the main challenges. In the future, in order to assist the industrial sector in better adapting to climate change, it is important to conduct more quantitative analyses, link the impacts of climate change on industry with adaptation strategies, consider the heterogeneity of regions, industries, and enterprises, construct models and evaluation systems to explore the complex underlying mechanisms of industrial climate adaptation.

The Intergovernmental Panel on Climate Change (IPCC) has accomplished all the assessment reports of the sixth assessment cycle (AR6). The synthesis report “Climate Change 2023” offers solid scientific support for the first Paris Agreement Global Stocktake, forming the “United Arab Emirates (UAE) Consensus” that guides global climate governance. Currently, both the IPCC and the Global Stocktake have embarked on a new cycle, and their work arrangements also basically coincide with the timeline of China’s “dual carbon” goals of “achieving carbon peak before 2030”. To better exert China’s leading role in global climate governance and gain the initiative in international climate governance from a scientific perspective, this paper commences from the major assessment achievements of the IPCC AR6 and the future planning of the AR7, combs through the cutting-edge scientific issues closely related to the Global Stocktake in the IPCC scientific assessment, and puts forward important insights such as scientifically promoting the transformation of the energy structure, paying attention to the security of energy and climate; highly valuing the assessment and reduction of non-CO₂ gases; strengthening adaptation actions, promoting the construction of adaptive cities; paying attention to climate tipping points, actively responding to new challenges of extreme climates, etc. It also presents development suggestions for the future in the fields of climate change mitigation, adaptation, and the natural science foundation. It is hoped to provide reference for our country to fully participate in the new round of IPCC climate change assessment and global climate governance.

The Paris Agreement completed its first global inventory at COP28, reached the UAE Consensus, and proposed the accelerated development of global renewable energy, the transition away from fossil energy, net zero emission energy system and other important content, demonstrating the outstanding role of energy transformation in achieving global climate goals. Significant achievements in global fossil energy consumption hindering energy transition, low-carbon energy technology becoming new growth point for global green low-carbon technology innovation, and global renewable energy investment promoting electrification rate have become the prominent characteristics of the current global energy transformation. At the same time, major economies attach great importance to energy transformation and technological innovation, making them as the main focus of long-term low emission strategy. The EU has launched new energy system and smart grid construction, Germany has taken multiple measures to promote fossil energy transformation, Japan continues to focus on hydrogen energy technology development, India develops consumption of renewable energy, and China has promoted the development of the new energy industry. The preliminary evaluation index system based on the energy transformation efforts and technological innovation capabilities of various countries shows that the EU and China are in the world’s top tier in energy transformation and technological innovation. To accelerate the global energy transformation and technological innovation process, countries should actively promote the implementation of long-term low emission strategy, establish a global funding mechanism for energy transition and technological innovation, accelerate the global green and low-carbon technology innovation sharing, and advance multilateral solutions for international cooperation.

This paper summarizes the key points of “Emirates Consensus” in the 28th Conference of the Parties (COP28) to the United Nations Framework Convention on Climate Change (UNFCCC) and analyzes the four declarations related to energy transition, focusing on renewable energy and energy efficiency, cooling, nuclear power, and green hydrogen. It emphasizes China’s role as a leader and a great contributor to global energy transition and COP28. It concludes that there are still some intense disagreements and conflicts such as the phase-out of fossil fuels and coal-fired power generation, the reduction of emissions in the power sector, earlier emissions peaking, and non-CO₂ greenhouse gases like methane, which will be the hard-debating and hot key-points in the coming negotiations. It is recommended that China further enhance national-level coordination and advance systematic planning, accelerate the energy supply and consumption revolution, actively and prudently promote carbon peaking and carbon neutrality, engage in global climate and energy governance, and expedite the development of China’s climate and energy transition negotiation team.

The continuous temperature rise and other issues caused by climate change have brought long-term risks and significant impacts to the world, and the economic losses caused by climate disasters are increasing day by day. Faced with the increasingly severe issue of climate change, countries have continuously raised their awareness of climate change adaptation, actively formulated national adaptation strategies and plans, strengthened action efforts, and achieved positive results. However, there is still a huge gap between the current global adaptation financing and the increasing cost of adaptation in developing countries, and there is an urgent need for in-depth support from the international community. China is the world’s largest developing country and one of the countries most severely affected by the adverse effects of climate change. In recent years, it has achieved certain results by continuously improving the strategic planning system for adapting to climate change, promoting the adaptation actions in key areas and regions. In the future, it is still necessary to further optimize the early warning system, strengthen climate risk management, lay a good foundation for domestic adaptation to climate change, and promote all parties to set long-term adaptation goals, strengthen financial support, and lead the world to jointly improve climate resilience.

In consideration of the gap between the goals of the Paris Agreement and global climate actions implied by the nationally determined contributions identified by the first Global Stocktake, utilizing international carbon pricing instruments to facilitate the GHG emission reduction activities, including market mechanisms, has become one of the key focus of international society. Besides the market mechanisms established by the Paris Agreement, IMF (International Monetary Fund), EU and other stakeholders have provided different policy proposals toward the arrangement of international carbon pricing. The analysis of different types of international carbon pricing policies shows that the market approach is more suitable for China. In order to improve impacts in carbon pricing area, it is suggested that China promote to enhance the framework of domestic carbon pricing mechanisms and facilitate the cooperation of cross border emission trading.

By using the electric rainproof shed at Gucheng station in Hebei province, natural precipitation is covered and irrigation is artificially controlled to form soil waterlogging, high humidity, drought and control. After summer maize flowering, the grain filling process, above-ground biomass, yield components, root-shoot structure and root-shoot ratio are measured. To explore the effects of soil drought and waterlogging stress on grain filling and yield formation of summer maize without the influence of rain and low-temperature stress. Analyze the source-sink relationship of dry matter in summer maize grain filling. The results show that the response of grain filling of summer maize to drought and waterlogging stress are different. The duration of filling days are longer under waterlogging (7-8 d longer than control) and shorter under severe drought (5-6 d shorter than control). For average grain filling rate, they are 9.19%-9.85% higher than control for high humidity, 24.80%-25.26% lower than control for severe drought, and 6.89%-7.45% lower than control for moderate drought. The dry matter of summer maize grain filling mainly comes from the photosynthetic products formed by photosynthesis such as green leaves at the filling stage, while the dry matter accumulated in the vegetative growth stage is less transported and accumulated in the grain. Previous studies failed to clearly reveal the source-sink matching relationship of corn grain filling. The plants of summer maize are still green leafy living stems from maturity to harvest, and the photosynthetic capacity is also strong, and the straw stock is large during harvest, which leads to decrease in harvest index. The transfer volume and contribution rate of different vegetative organs on the above-ground of summer maize plants to grain filling are tested and analyzed. It was found that the contribution rate of different vegetative organs under drought and water stress is higher than control, but the economic yield is reduced, which indicated that the transfer volume and contribution rate of vegetative organs under drought and waterlogging stress could not really reflect the biological influence on the yield formation. Drought and waterlogging stress have different effects on photosynthetic physiological characteristics of ear leaves in summer maize filling stage. Net photosynthetic rate (P_n) is 0.91%-9.10% higher than the control under waterlogging, and 1.75%-9.13% lower than the control under high humidity. Drought is significantly lower than the control: 55.76%-59.08% lower in moderate drought, 92.16%-92.75% lower in severe drought. Drought has greater influence than high humidity. Leaf water use efficiency (WUE) is significantly decreased under severe drought condition, which is 60.40%-64.75% lower than control. Drought and waterlogging stress have negative effects on the formation of summer maize yield: the yield reduction rate of waterlogging and high humidity is 1.83%-8.43%, the yield reduction rate of drought treatment is 32.73%-81.96%, and the severe drought almost resulted in no harvest. The damage degree of drought is much greater than that of waterlogging and high humidity. Drought stress stimulated and induced the proliferation of fibrous roots in maize roots, and the weight of fibrous roots increased significantly, resulting in an increase in the root-shoot ratio. In particular, severe drought is more than 10 times higher than waterlogging, high humidity and control, indicating that maize roots, in particular, must have physiological regulatory mechanisms for emergency response to soil waterlogging stress and survival mechanisms to adapt to adverse conditions. Improve the function of absorbing water and nutrients, and enhance the support and lodging resistance of the root system to the plant. The research results provide data support and reference for assessing the effects of drought and flood disasters on crop growth and yield formation in northern arid regions, and taking agricultural measures to enhance the ability of disaster resistance and reduction and the coefficient of stable grain yield.

In the process of global climate governance of last thirty years, there hasn’t been accurate definition of climate finance, while the connotation of which has been evolved significantly. In this study, a climate finance analyzing framework was established with 4 dimensions and 10 indicators, including dimensions on origin, quantity, flow direction and usage, and indicators of geographic boundary, legal character, nominal quantity, real quantity, specific accounting requirements induced by laws, provider, recipient, channel, purpose, and financial instrument, which was then applied to analyze the evolution of climate finance under global governance. It is found that the most significant evolution is the changing of climate finance as mandatory obligation of Parties included in the Annex II of the UNFCCC to two different connotations, i.e., climate finance as obligation under international law and climate finance as global action. It is also found the difference in the order of magnitude among climate finance estimation, reporting and initiative is mainly caused by scope ambiguity and inconsistency of accounting standards. It is then recommended to acknowledge the two different definitions of climate finance, establish unified climate finance accounting methodology across the world, and enhance transparency of climate finance information, in order to enhance the implementation of obligations and responsibilities on climate finance under international climate treaties, as well as to enhance international cooperation.