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Mangrove ecosystems are becoming increasingly important in global climate mitigation. However, large gaps still exist in evaluating mangroves' gross primary productivity (GPP) due to reasons such as the specific influences, for example, temperature and salt stresses are poorly described in Earth System Models (ESMs). This study developed a process‐based biogeochemical model (Mango‐GPP) to improve the GPP simulation in natural and restored mangroves. The model integrates mangrove‐specific physiological processes, including the response to salt and temperature stresses, as well as the light‐use efficiency at different growing stages. Eddy covariance flux measurements at two natural sites and one restored site in China were used to calibrate and validate Mango‐GPP. The model was calibrated by inverse analysis approach based on two cases and independently validated against the other cases. The validation results showed that it was generally capable of simulating the seasonal and interannual GPP variations at different sites. The simulated daily and annual GPPs agreed well with the observations and yielded R2 of 0.67 and 0.96, with model efficiency of 0.64 and 0.93, respectively. In comparison, Mango‐GPP showed better performances than many current satellite‐based GPP products and ESMs. The model was more sensitive to solar radiation, carbon dioxide concentration, and leaf traits. Future improvements should focus on enhancing Mango‐GPP's descriptive power of key processes, and further simulating other carbon fluxes at regional scales. This work provides a model foundation for further simulating carbon exchanges between the atmosphere, mangrove, and ocean for studying the coastal wetland restoration on regional carbon neutrality. Plain Language Summary: Mangroves are becoming increasingly important for climate mitigation, but are greatly under‐represented in current ecosystem models. This study developed a new process‐based model (Mango‐GPP) to specifically estimate carbon taken up by mangrove ecosystems. The model requires few and easily accessible inputs, and showed good performance in both natural and restored mangroves. This work sets the stage for future studies on impacts of mangrove changes (e.g., restoration and reestablishment etc.) on carbon sequestration and climate mitigation. Key Points: We developed a process‐based model simulating daily gross primary productivity (GPP) for mangrovesThe model incorporates the effects of salinity and temperature, as well as light absorption and use efficiency on mangroves' GPPThe model requires only 13 easily accessible inputs and is validated well at both natural and restored mangroves in China [ABSTRACT FROM AUTHOR]

Harbin, located in northeast China (NEC), has obvious monsoon climate characteristics due to the influence of its geographical environment. Under the control of the polar continental air mass, winter in Harbin is exceedingly cold and long, with the frequent invasion of the cold and dry air from the north. Because of its intensely cold climate in winter, Harbin has created a local form of tourism with its own characteristics: the snow and ice landscape attracts a large number of tourists. Therefore, the anomalies of air temperature and precipitation in winter have an important impact on the livelihood of the local people and economy. In the winter of 2018/2019, the ice and snow tourism in Harbin was harshly affected by the extreme weather, and the direct cause is the anomalies of atmospheric circulation. There is a center of strong positive geopotential height anomalies over east China, which favors the movement of warm air northwards to the NEC, resulting in warmer-than-normal air temperature. Anomalous precipitation is largely controlled by the anomalies of local water vapor and air temperature. The aim of this study was to determine whether the warmer-than-normal temperature, which made the atmosphere more resistant to saturation, was the primary cause of the reduced snowfall. The relative importance of water vapor and air temperature anomalies to the anomalous precipitation was compared. The results suggest that the warmer-than-normal temperature affected all levels, but its impact on the near-surface level was greater. At the middle and upper levels (above 850 hPa), in addition to the warmer-than-normal temperature, the amount of water vapor was less than normal. These conditions both reduced the amount of snow; however, by comparison, the dryness of the air contributed more significantly. [ABSTRACT FROM AUTHOR]

In the context of global warming, the impact of summer high temperature events is increasing. The accumulated summer high temperature is often used to reflect the overall hotness of summer. The internal variation of the accumulated temperature can be affected by both the frequency and intensity. In this study, by using the daily data during summers of 1960–2018, we examine the relative importance of the two factors with a multiple linear regression method. It is demonstrated that that the dominant result of summer accumulated temperature is sensitive to the change of threshold. As the threshold increases, the importance of frequency gradually increases, while the importance of the intensity decreases. In addition, it is found that when the threshold changes, the sensitivity of the dominant results is different over regions. This can provide a basis for the selection of regional thresholds and further improve the representation of accumulated temperature for high summer temperatures. [ABSTRACT FROM AUTHOR]

Freezing level height (FLH) is the altitude of a location where the air temperature is 0°C. The FLH denotes the approximate position for water phase transitions from liquid (or vapour) to solid but not vapour to liquid. Based on temperature and height data on the ground surface to heights with an atmospheric pressure of 400 hPa, the monthly FLH at 118 radiosonde stations located in China are derived for the 1958–2017 period. The monthly and annual climatology during 1981–2010 and the seasonal, intra‐annual and decadal variabilities of the FLH during 1958–2017, along with its long‐term trends, were quantitatively evaluated at the regional scale and for individual stations. FLH climatology is generally related to season, zone and topography. The annual FLH anomalies decline initially, followed by a rise, with synchronous changes in the temperature in the lower and middle troposphere; the anomalies in south‐eastern China are partly associated with El Niño–Southern Oscillation events. The increasing trends of FLH are closely associated with tropospheric warming and show evident regional and seasonal differences. Stronger increasing trends are observed in northern and western China in autumn or winter (particularly in recent decades). The changes in FLH have implications on long‐term trends in equilibrium line altitude (ELA) of glaciers in Tianshan Mountains, snow cover extent in melt season and hail frequency in China especially in high‐elevations. During recent decades, the evolution of the FLH and major composition in the cryosphere has accelerated as a response to tropospheric warming. The study on FLH change can provide valuable information for the evaluation of glaciers, snow cover extent and hail frequency in China from a new perspective; which is helpful for understanding regional hydrological processes and climate changes better. Further application of FLH in cryosphere monitoring can improve water management and flood forecasting in headwater regions in China. [ABSTRACT FROM AUTHOR]

Beginning in 2016, all couples in China were allowed to have two children without any restrictions. This paper provides population and economic projections under five shared socioeconomic pathways (SSPs) and three fertility policies. By replacing the one‐child policy with the two‐child policy, the population is predicted to continue growing until 2025–2035, with a peak of approximately 1.39–1.42 billion, and then to decline under four SSPs, with the exception of the fragmented world SSP3. As a result, the two‐child policy will lead to mitigation of the pressure from labor shortages and aging problems to a certain extent. In addition, an increase in working‐age people with higher education level relative to projections based on the one‐child policy will lead to an increase in gross domestic product by approximately 38.1–43.9% in the late 21st century. However, labor shortages and aging problems are inevitable, and the proportion of elderly in China will be greater than 14% and 21% by approximately 2025 and 2035, respectively. Full liberalization of fertility is expected to reduce the share of elderly people by 0.7–1.0% and to lead to an increase in gross domestic product by 5.3–6.7% relative to the two‐child policy in the late 21st century. The full liberalization of fertility policies is recommended, supplemented by increases in pension and child‐rearing funds, improvement in the quality of health services for females and children, and extension of compulsory education to meet the needs of an aged society. Plain Language Summary: The one‐child policy in China has been replaced by the two‐child policy since 2016. What might the population and economy change if the one‐child policy is continued in the 21st century? What can China benefit from the fertility policy changes? Is it necessary to allow people to choose their family size in China? We conducted multipopulation policies and multisocioeconomic development pathways combined analysis to explore the effects of fertility policy changes on population and economy in China. We found that population size by the late 21st century might be 28% less than that in 2010 at the one‐child policy, and share of elderly (aged 65+) might be 49%. The implementation of the two‐child policy can mitigate the labor shortages and aging problems to a certain extent, and the increased working‐age population with higher education level can lead to a 38.1–43.9% increase in gross domestic product in the late 21st century. A further 0.7–1.0% reduction in elderly share of the total population and 5.3–6.7% increase in gross domestic product is projected in the late 21st century at the "full relaxation" policy. We believe that introduction of effects from fertility policy changes on socioeconomy can deliver useful information to decision makers. Key Points: The integrated effects of population policies and socioeconomic pathways on the population structure and economy are exploredThe population bust in China caused by the one‐child policy will be relieved after the two‐child policy, as indicated by all the SSPsFull relaxation of fertility control is recommended with the simultaneous implementation of other social policies (e.g., pension funds) [ABSTRACT FROM AUTHOR]

• The technical potential of wind and solar to power China was quantified accurately. • Wind and solar alone are able to meeting 67% of China's electricity demand by 2050. • Flexible grid connection substantially improves renewable energy penetration rate. • Recommend policymakers accelerate exploiting complementary wind and solar power. China's goal of being carbon-neutral by 2060 requires a green electric power system dominated by renewable energy. However, the potential of wind and solar alone to power China remains unclear, hindering the holistic layout of the energy development plan. Here, after taking temporal matching of supply and demand (60 min), land use, and government policy into account and assuming lossless transmission, we demonstrate that deploying wind and solar capacity of 2495 and 2674 GW, respectively, within flexible and optimized grids can meet ∼67% of electricity demands by all society sectors for 2050 (∼6.3% curtailment rate), even without other costly power sources or storage. Spatially explicit configurations of the grids are provided simultaneously to support this achievement. The resulting green electricity supply of 10.4 PWh per year help secure China's carbon-neutral goal and reduces 2.08 Mt SO 2 and 1.97 Mt NOx emissions annually. Our findings recommend policymakers accelerate exploiting complementary wind and solar power as the dominant source of energy. [ABSTRACT FROM AUTHOR]

Climate warming and subsequent climate extremes have a wide impact on ecosystems and economic society. Scientifically quantitative assessment on climate change risks is an urgent issue attracted the attention of academics and decision-makers. In this paper, the theory of climate change risks was sorted out based on the three component elements of hazard, vulnerability, and exposure. Moreover, the idiomatic assessment methods and their applicability were systematically summarized. Comprehensive analysis found that the impacts of climate change generally showed a negative trend that was more harm than benefit, and further warming would aggravate the risk over China which was manifested to be more prominent in some sensitive sectors and key regions to climate change. Accessible management of the climate change risk should be engaged in effectively improving the methods of comprehensive identification, strengthening the mechanism and quantitative assessment, recognizing the temporal and spatial variation of components related to climate change risk, and reducing the uncertainty of climate change projection. • Theoretical framework of climate change risk was formed based on hazard, vulnerability, and exposure. • Assessment methods of climate change risk and their applicability were systematically summarized. • Climate change risk levels were analyzed in sensitive sectors and key regions over China. • In China, impacts of climate change were more harm than benefit while more warming was very likely to aggravate the risk. [ABSTRACT FROM AUTHOR]

To achieve the national objective of "carbon peak and carbon neutrality," it is imperative to significantly enhance the utilization of renewable energy sources, such as wind and solar power, in the transformation of China's energy infrastructure. However, the intermittent, volatile, and unstable nature of wind and solar power generation systems is often subject to the influence of local weather conditions. Furthermore, recent years have witnessed a growing frequency and intensity of extreme weather events, posing considerable constraints on the effective exploitation of wind and solar resources. Consequently, conducting a comprehensive climate risk analysis pertaining to wind and solar resources is of paramount importance in expediting their adoption while mitigating potential energy security risks. In this study, we conducted an extensive examination of inefficient wind and solar resources across China, encompassing the intensity, spatial distribution, and duration of such events. Leveraging high-resolution wind and solar resource datasets spanning from 2000 to 2021, we employed intensity-area-duration analysis to elucidate the spatial and temporal characteristics of these inefficiencies nationwide. Moreover, we conducted a diagnostic assessment of key factors, including scope, duration, and frequency. Additionally, we proposed a comprehensive index system to evaluate the viability of wind and solar resource development. Our findings revealed that climate risks associated with wind and solar resources were predominantly concentrated in autumn and winter. Regions such as Xinjiang, Sichuan, and the middle reaches of the Yangtze River exhibited a higher frequency of inefficient wind and solar events. Notably, the North China Plain and the middle reaches of the Yangtze River were primarily affected by haze and plum rain weather, respectively, leading to these inefficiencies. Conversely, the northwest and northeast regions demonstrated a superior suitability for wind and solar resource development. This study provides valuable scientific insights for guiding the selection of optimal locations for wind and solar power plants, as well as the development of regional renewable energy infrastructure in China. • Wind and solar resource fluctuations were assessed using high-resolution datasets across China. • The intensity-area-duration (IAD) method was employed. • An index system was proposed to evaluate the suitability of wind and solar resource. • The insufficient resource events have seasonal variations and spatial disparities. • Inner Mongolia and Xinjiang have great potential for renewable energy development. [ABSTRACT FROM AUTHOR]

China and Germany have a long history of collaborating in the Earth sciences. Collaboration is working through the development of research programs based on the strong scientific foundation of the national climate capacity of Germany and the climate science research network of China. China and Germany can contribute to the GFCS by developing and incorporating science-based climate information and prediction into planning, policy and practice at regional and national scales. [Extracted from the article]

Background: Studies on the associations between temperature and osteoporotic fractures (OF) hospitalizations are limited. This study aimed to assess the short-term effect of apparent temperature (AT) on the risk of OF hospitalizations., Methods: This retrospective observational study was conducted in Beijing Jishuitan Hospital from 2004 to 2021. Daily OF hospitalizations, meteorological variables and fine particulate matter were collected. A Poisson generalized linear regression model combined with a distributed lag non-linear model was applied to analyze the lag-exposure-response relationship between AT and the number of OF hospitalizations. Subgroup analysis by gender, age and fracture type was also conducted., Results: Total daily hospitalization visits for OF during the studied period were 35,595. The exposure-response curve of AT and OF presented a non-linear relationship, with optimum apparent temperature (OAT) at 28.40 °C. Taking OAT as the reference, the cold effect (-10.58 °C, 2.5th percentage) on single lag day had statistical significance from the current day of exposure (RR = 1.18, 95 % CI: 1.08-1.28) to lag 4 day (RR = 1.04, 95 % CI: 1.01-1.08), while the cumulative cold effect increased the risk of OF hospitalization visits from lag 0 to 14 days, with the maximum RR over lag 0-14 days (RR = 1.84, 95 % CI: 1.21-2.79). There were no significant risks of OF hospitalizations for warm effects (32.53 °C, 97.5th percentage) on single or cumulative lag days. The cold effect might be more evident among females, patients aged 80 years or older, and patients with hip fractures., Conclusion: Exposure to cold temperatures is associated with an increased risk of OF hospitalizations. Females, patients aged 80 years or older and patients with hip fractures might be more vulnerable to the cold effect of AT., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Wetlands are large sinks of carbon dioxide (CO 2 ) and sources of methane (CH 4 ). Both fluxes can be altered by wetland management (e.g., restoration), leading to changes in the climate system. Here, we use multiple models to assess CH 4 emissions and CO 2 sequestration from the wetlands in China and the impacts on climate under three climate scenarios and four wetland management scenarios with various levels of wetland restoration in the 21st century. We find that wetland restoration leads to increased CH 4 emissions with a national total of 0.32-11.31 Tg yr -1 . These emissions induce an additional radiative forcing of 0.0005-0.0075 W m -2 yr -1 and global annual mean air temperature rise of 0.0003-0.0053 °C yr -1 , across all future climate and management scenarios. However, wetland restoration also resulted in net CO 2 sequestration, leading to a combined net greenhouse gas sink in all climate management scenarios, except in the highest restoration level combined with the hottest climate scenario. The highest climate cooling was achieved under medium restoration, with the climate scenario consistent with the Paris agreement target of below 2 °C, with a cumulative global warming potential of -3.2 Pg CO 2 -eq (2020-2100). Wetland restoration in the Qinghai-Tibet Plateau offers the greatest cooling effect.