Based on global climate models from Coupled Model Intercomparison Projection Phase 6 (CMIP6) under SSP1-1.9 scenario, the changes in mean temperature and precipitation, as well as seven extreme climate indices, over the 23 subregions at 1.5℃level (P1 phase) and cooled to 1.5℃ level (P2 phase) were projected. Results show that the differences of temperature, precipitation, and extreme climate events between P1 and P2 phases show good agreement worldwide among multiple models, with obvious regional and local features. Multi-model consistent changes in temperature extremes generally approach or exceed 15% of the global land area. The spatial pattern of extreme cold events differences between two phases is similar to that of winter mean temperature, and the distribution of extreme hot events shows the local character. Globally, the areas with multi-model consistent increases in both cold and hot events are larger than those with the decreases. The risk of extreme cold/hot events will increase over the western part of mid-high latitudes in Eurasia, North America and northeastern China/the Tibet Plateau, eastern China, South Asia, East Africa, North America and Antarctic. Multi-model consistent changes in precipitation extremes generally exceeds 20% of global land area, but the area with increases is close to that with decreases. The spatial pattern of heavy precipitation differences is partially similar to that of annual mean precipitation: the values over southern China, South Asia, Southeast Asia, eastern and southwestern South America, North America, Australia, and central and eastern Europe will increase with good agreement, and the values over North China to northeastern China, southern edge of the Tibet Plateau, southern Africa, northern South America and northern Australia will decrease with good agreement. More consecutive dry days (CDDs) are projected in most regions, the large changes with good agreement can be found over Central Asia, South Asia, the Tibet Plateau, central and northern Russia, north of Sahara in Africa and central Africa, central Australia, parts of Antarctic. It indicates that even if global carbon emission peaks before 2030 and then begins to reduce immediately, temperature and precipitation extremes at certain regions will be even larger than those before overshooting, due to the diverse regional climate responses to global warming. Then the impact will still last many years, with the influence increasing. Thus, the projected increases in extreme climate events on regional and local scale should be alerted.

Northwest China experiences a scarcity of annual precipitation, characterized as a typical inland arid and semi-arid region. In recent years, various evidence has indicated an increasing trend in precipitation in this region. Understanding how precipitation will change in Northwest China under future warming has become a topic of widespread concern in the academic and social spheres in China. Based on two physically constrained (preferred) methods, namely, the emergent constraint and the Pareto-optimal ensemble scheme, two influential physical factors affecting summer precipitation in Northwest China were selected: tropical Indian Ocean sea surface temperature (SST) and the East Asian subtropical 200 hPa zonal wind. Different constraint schemes were applied to the summer precipitation projections from 25 CMIP6 models. The results show that, relative to the period 1995-2014, the ensemble mean of CMIP6 models projects a 23% increase in average summer precipitation in Northwest China by the end of the 21st century. The unconstrained estimation range is from -8.4% to 61.7%. After constraining with tropical Indian Ocean SST (East Asian subtropical 200 hPa zonal wind), the projected increase reaches 24% (19%), and the uncertainty range narrows to -8.4% to 52% (-9% to 45%), reducing uncertainties by 15% (21%). Further utilization of the three-variable Pareto-optimal ensemble scheme, including historical summer precipitation in Northwest China, tropical Indian Ocean SST, and East Asian subtropical 200 hPa zonal wind, indicates a 28% increase in average summer precipitation in Northwest China by the end of the 21st century, with a narrowed uncertainty range of 8% to 44%, representing a nearly 39% reduction in uncertainty. The Pareto-optimal ensemble suggests that the regions experiencing increased precipitation are concentrated in the central and western parts of Northwest China, with the maximum precipitation increase exceeding 60%.

Human activities lead to increase in atmospheric CO₂ concentrations and global warming, threatening human survival. As a potential method to mitigate global warming, CO₂ removal has garnered extensive attention in recent years. We employed the University of Victoria Earth System Climate Model (UVic ESCM) to simulate and analyze the effects of both positive and negative CO₂ pulses of various intensity on the carbon cycle starting from preindustrial equilibrium (CO₂ concentration: 285×10^-6). The results show that in the 100 Pg C positive CO₂ pulse emission scenario, 100 (1000) years after imposing the CO₂ pulse, only 28% (18%) of the CO₂ emission remains in the atmosphere, the ocean absorbs about 38% (61%) of the CO₂ emission, the land absorbs about 34% (21%) of the CO₂ emission. In the 100 Pg C negative CO₂ pulse emission scenario, the ocean and the land releases CO₂ to the atmosphere, weakening the effect of CO₂ removal. 100 (1000) years after imposing the CO₂ pulse, only 23% (12%) of the initial CO₂ removal from the atmosphere remains, with 36% (65%) offset by ocean carbon release, 41% (23%) offset by land carbon release. According to different positive and negative pulse scenarios, the cumulative airborne fraction in the positive pulse scenario is always higher than cumulative removal fraction in the negative pulse scenario of the same intensity, which indicates that the positive and negative pulse carbon emission scenario responses of the sea and land carbon cycles are asymmetric. It means that negative emissions of higher intensities are needed to offset the atmospheric CO₂ concentration increases caused by positive emissions.

Based on the basic theory of the impact of climate risk on product prices in futures market and the combination of text analysis and GARCH model, the impacts of climate risk on product prices in futures market were quantitatively evaluated by taking four kinds of macroeconomic factors into account. The results show that, the climate risk index has a positive correlation with the price index of energy and chemical futures, and climate risk has risk spillover effect on both energy futures and chemical futures markets. The current climate risk index has a significant positive impact on the yield of agricultural, energy and chemical futures price index, and a significant negative impact on the yield of grain futures price index. The current climate risk index has a significant positive impact on the yield volatility of agricultural futures price index, and a significant negative impact on the yield volatility of grain, chemical and energy futures price index. The research results reveal the complex impact of climate risks on futures markets and help provide scientific basis for financial markets to cope with climate risks.

The impact of carbon emissions is global, posing a threat to global climate, ecological balance, human health and other aspects. Digital economy is being integrated into various fields of economic and social development, and its impact on carbon emissions deserves attention and exploration. In order to verify the complex internal influence path between digital economy and carbon emissions, this study successively adopts the two-way fixed effects model with time and individual effects, the mediation model, the threshold effect model and the spatial Durbin model. The empirical results show that: first, digital economy can significantly inhibit carbon emission intensity and per capita carbon emissions; Second, the digital economy can help adjust the energy structure, thus significantly reducing carbon emissions. Third, with the improvement of energy efficiency, digital economy and carbon emissions show an inverted U-shaped relationship. Fourthly, under three spatial weight matrices, the effects of digital economy on carbon emission show spatial spillover effect. The conclusions of this study provide reference for further promoting the development of digital economy and realizing China’s “Dual Carbon” goals.

Carbon emission reduction in the civil aviation industry is a complex issue involving economic, social, technological and environmental aspects. The implementation of pathway simulation based on a systems approach will help to optimize the sustainable plan for Chinese civil aviation industry. To quantitatively identify the carbon reduction effects and costs, a system dynamics (SD) model based on civil aviation decarbonization was developed, with full consideration of elemental and sub-system compositions, and scenarios were simulated and explored to determine the effects of the carbon reduction pathways and implementation costs of the civil aviation industry. The results showed that the single policy simulation scenarios of the industry’s implementation of energy-saving technology advancement, alternative fuel application, promotion of new power energy, carbon offset mechanism and high-speed rail substitution cannot achieve the industry’s carbon-neutral long-term development goal. The combination policy of multiple measures provided the optimal comprehensive decarbonization program for the industry’s decarbonization development. In the future, the industry should actively promote the large-scale application of sustainable aviation fuel (SAF) in the short term, increase the research and development of hydrogen, electricity and hybrid aircraft in the medium term, actively adopt integrated transportation modes such as high-speed rail substitution, and continue to improve the energy-saving and emission-reduction technologies of the industry in the long term, as well as promote the incorporation of the civil aviation industry into the national carbon market. The results of the study can provide a reference for policy formulation for the sustainable development of the civil aviation sector, and help the industry decarbonize deeply.

Transition finance plays an important role in supporting the green transformation of high-carbon enterprises and coping with climate change. As an important and emerging financial field, exploring its legalization path can provide an important reference for the construction of China’s transition finance system. By combing the emergence and development of transition finance, and drawing on the legislative experience of the European Union in the field of transition finance, the legalization path of the legal system of transition finance is discussed in the light of China’s actual situation. Considering the legislative practice, policy status quo, market practice experience and legislative cost, it is more appropriate to incorporate the legal system of transition finance into the legal system of green finance. In terms of legislative path, China should introduce the principle clauses of transition finance into the general provisions and sub-provisions of the Green Finance Law, and complement it with the implementation of low-ranking legislation on transition finance. In terms of institutional arrangements, we should clarify the catalog of supportive financial activities, the mechanism for auditing and disclosure of transformational activities, the legal liability system and other supporting systems through multi-level legislation, and think about the synergistic paths of transformational finance laws and policy systems.

Taking Aniji county of Zhejiang province as a case study, an evaluation index system was constructed, and the economic value and functional quantity of gross climate ecosystem product were calculated from four categories: climate resources exploitation value, climate regulation service value, climate carbon fixation and oxygen release value, and climate brand added value. The total value of gross climate ecosystem product of Anji in 2022 was CNY 25.908 billion, accounting for 44.49% of its GDP (CNY 58.237 billion). Of which, climate resources exploitation value was CNY 1.335 billion, accounting for 5.15%; climate regulation service value was CNY 16.711 billion, accounting for 64.50%; climate carbon fixation and oxygen release value was CNY 3.388 billion, accounting for 13.08%; climate brand added value was CNY 4.474 billion, accounting for 17.27%. The total potential value of water resources, wind resources and solar resources was 28.143 billion kW?h, with a total value of CNY 14.152 billion. The results show that the accounting of gross output value of climate ecosystems can monetize the state and changes of Anji’s climate ecosystems, and provide evaluation reference for local green development planning and climate change adaptation.