Pollutant emissions in China have significantly decreased over the past decade and are expected to continue declining in the future. Aerosols, as important pollutants and short-lived climate forcing agents, have significant but currently unclear climate impacts in East Asia as their concentrations decrease until mid-century. Here, we employ a well-developed regional climate model RegCM4 combined with future pollutant emission inventories, which are more representative of China to investigate changes in the concentrations and climate effects of major anthropogenic aerosols in East Asia under six different emission reduction scenarios (1.5 degrees C goals, Neutral-goals, 2 degrees C -goals, NDC-goals, Current-goals, and Baseline). By the 2060s, aerosol surface concentrations under these scenarios are projected to decrease by 89%, 87%, 84%, 73%, 65%, and 21%, respectively, compared with those in 2010-2020. Aerosol climate effect changes are associated with its loadings but not in a linear manner. The average effective radiative forcing at the surface in East Asia induced by aerosol-radiation-cloud interactions will diminish by 24% +/- 13% by the 2030s and 35% +/- 13% by the 2060s. These alternations caused by aerosol reductions lead to increases in near-surface temperatures and precipitations. Specifically, aerosol-induced temperature and precipitation responses in East Asia are estimated to change by -78% to -20% and -69% to 77%, respectively, under goals with different emission scenarios in the 2060s compared to 2010-2020. Therefore, the significant climate effects resulting from substantial reductions in anthropogenic aerosols need to be fully considered in the pathway toward carbon neutrality.

Tea is a vital agricultural product in Taiwan. Due to global warming, the increasing extreme weather events have disrupted tea garden conditions and caused economic losses in agriculture. To address these challenges, a comprehensive tea garden risk assessment model, a Bayesian network (BN), was developed by considering various factors, including meteorological data, disaster events, tea garden environment (location, altitude, tea tree age, and soil characteristics), farming practices, and farmer interviews, and constructed risk assessment indicators for tea gardens based on the climate change risk analysis concept from the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5). The results demonstrated an accuracy of over 92% in both validating and testing the model for tea tree damage and yield reduction. Sensitivity analysis revealed that tea tree damage and yield reduction were mutually influential, with weather, fertilization, and irrigation also impacting tea garden risk. Risk analysis under climate change scenarios from various global climate models (GCMs) indicated that droughts may pose the highest risk with up to 41% and 40% of serious tea tree growth damage and tea yield reduction, respectively, followed by cold events that most tea gardens may have less than 20% chances of serious impacts on tea tree growth and tea yield reduction. The impacts of heavy rains get the least concern because all five tea gardens may not be affected in terms of tea tree growth and tea yield with large chances of 67 to 85%. Comparing farming methods, natural farming showed lower disaster risk than conventional and organic approaches. The tea plantation risk assessment model can serve as a valuable resource for analyzing and offering recommendations for tea garden disaster management and is used to assess the impact of meteorological disasters on tea plantations in the future.

In the context of China's dual carbon goal, emissions of air pollutants are expected to significantly decrease in the future. Thus, the direct climate effects of black carbon (BC) aerosols in East Asia are investigated under this goal using an updated regional climate and chemistry model. The simulated annual average BC concentration over East Asia is approximately 1.29 mu g/m(3) in the last decade. Compared to those in 2010-2020, both the BC column burden and instantaneous direct radiative forcing in East Asia decrease by more than 55% and 80%, respectively, in the carbon peak year (2030s) and the carbon neutrality year (2060s). Conversely, the BC effective radiative forcing (ERF) and regional climate responses to BC exhibit substantial nonlinearity to emission reduction, possibly resulting from different adjustments of thermal-dynamic fields and clouds from BC-radiation interactions. The regional mean BC ERF at the tropopause over East Asia is approximately +1.11 W/m(2) in 2010-2020 while negative in the 2060s. BC-radiation interactions in the present-day impose a significant annual mean cooling of -0.2 to -0.5 K in central China but warming +0.3 K in the Tibetan Plateau. As China's BC emissions decline, surface temperature responses show a mixed picture compared to 2010-2020, with more cooling in eastern China and Tibet of -0.2 to -0.3 K in the 2030s, but more warming in central China of approximately +0.3 K by the 2060s. The Indian BC might play a more important role in East Asian climate with reduction of BC emissions in China.

The volumetric change in unsaturated loess during loading causes serious damage to the foundation and structure, accompanied by changes in hydraulic conditions. Therefore, quantifying the change in the load effect of loess under hydraulic coupling is of great significance for revealing the mechanism of hydraulic interaction. This study conducts isotropic compression and undrained shear tests on unsaturated compacted loess, simultaneously introducing the strength parameter eta to enhance the Glasgow coupled model (GCM). The objective is to elucidate the hydraulic and mechanical coupling mechanism, where saturation increases under mechanical effects lead to strength degradation. The results show that saturation increases under mechanical effects improve the compressibility of the sample, and saturation has a direct impact on the stress-strain relationship. The increase in water content and confining pressure increases the trend of the critical state stress ratio M decreasing, and the strain softening trend increases. The compression of volume during shear tests increases the saturation, changes the hydraulic characteristics of loess, and affects the deformation and strength of loess. The modified GCM improves the applicability and prediction accuracy of unsaturated loess under the same initial state. The research results are of great significance for revealing the hydraulic and mechanical behavior of loess.

The decadal variability of direct radiative effects of aerosols is investigated at Dibrugarh, a site in northeast India (NEI) at the eastern Himalayan foothills, primarily using multi-wavelength solar radiometer measurements spanning from October 2001 to February 2020. The ground-based aerosol observations are combined with satellite remote sensing, reanalysis data, and model simulations to study the change in atmospheric particle loading over the region. Observations indicate a statistically significant increase (similar to 0.015 yr(-1)) in Aerosol Optical Depth (AOD) during the last two decades in line with an increase in human activity. As compared to 2001-2007 (we call it as Stage I), the aerosol burden has grown rapidly during 2008 until 2020 (Stage II). AOD at 500 nm is found to increase by similar to 40% from Stage I to Stage II, resulting in an increase in the aerosol direct radiative forcing (DRF) at the top of the atmosphere (TOA) by similar to 43% during stage II (similar to-16.0 W m(-2)), from the base value of -11.2 W m(-2) in Stage I. Decreasing biomass burning activities, black carbon aerosol mass concentration, and high sulfate and organic aerosols are the primary factors responsible for the trend in TOA cooling by-0.46 W m(-2) yr(-1). This is further aided by the decrease in rainfall over NEI. MERRA-2 data analysis shows a similar enhancements in aerosol load over the entire NEI and the adjacent highly polluted Indo-Gangetic Plains (IGP). A similar feature is seen over the IGP, primarily driven by anthropogenic emissions, but precedes that in NEI by about a year. A simulation of the regional climate model (RegCM) over the south Asian domain quantifies the contribution of aerosol loading over NEI due to the aerosols carried from the IGP. In the highest aerosol loading period, about 12-30% of the aerosols, equivalent to 15-30% of atmospheric warming, are transported from the IGP to the NEI.

文章应用全球气候模型，探究环境生态中有关CO2排放量与未来全球气候变化的关联性，分析并预测未来全球气候的变化趋势。采取控制变量的方法即向模型系统输入3种不同的CO2排放情景，应用EdGCM软件模拟计算CO2在正常排放和极端排放情况下，地表大气温度、降雨量和积雪覆盖率3个不同的环境生态表征量对于CO2排放的反馈；在对模拟结果进行分析与比较基础上，预测CO2排放对未来全球气候变化的影响程度。研究结果可为全球各地区制定相关的环境政策提供参考。

文章应用全球气候模型，探究环境生态中有关CO2排放量与未来全球气候变化的关联性，分析并预测未来全球气候的变化趋势。采取控制变量的方法即向模型系统输入3种不同的CO2排放情景，应用EdGCM软件模拟计算CO2在正常排放和极端排放情况下，地表大气温度、降雨量和积雪覆盖率3个不同的环境生态表征量对于CO2排放的反馈；在对模拟结果进行分析与比较基础上，预测CO2排放对未来全球气候变化的影响程度。研究结果可为全球各地区制定相关的环境政策提供参考。

Heat waves in India during the pre-monsoon months have significant impacts on human health, productivity and mortality. While greenhouse gas-induced global warming is believed to accentuate high temperature extremes, anthropogenic aerosols predominantly constituted by radiation-scattering sulfate are believed to cause an overall cooling in most world regions. However, the Indian region is marked by an abundance of absorbing aerosols, such as black carbon (BC) and dust. The goal of this work was to understand the association between aerosols, particularly those that are absorbing in nature, and high-temperature extremes in north-central India during the pre-monsoon season. We use 30-year simulations from a chemistry-coupled atmosphere-only general circulation model (GCM), ECHAM6-HAM2, forced with evolving aerosol emissions in an interactive aerosol module, along with observed evolving SSTs. A composite of high-temperature extremes in the model simulations, compared to climatology, shows large-scale conditions conducive to heat waves. Importantly, it reveals concurrent positive anomalies of BC and dust aerosol optical depths. Changes in near-surface properties include a reduction in single scattering albedo (implying greater absorption) and enhancement in short-wave heating rate, compared to climatological conditions. Alterations in surface energy balance include reduced latent heat flux, but increased sensible heat flux, consistent with enhanced temperatures. Thus, chemistry-coupled GCM simulations capture an association of absorbing aerosols with high-temperature extremes in north India, arising from radiative heating in the surface layer.

青藏高原积雪变化对陆面能量水分传输过程有重要影响。本文采用RegCM4.7-CLM4.5模式模拟了高原及其周边地区31年的积雪过程,通过对模拟结果的EOF分解,发现高原积雪的时空变化主要呈现为高原主体与高原东北部反相、东西反相以及南北反相3种模态,方差贡献率分别为30.05%,14.86%和8.48%。合成分析显示,高原积雪异常中心与高原的主要积雪区较为一致,积雪深度与积雪日数均有减小的气候倾向,高原东南部的"三江源区"减小趋势最明显,高原中北部积雪有略微增加的趋势。积雪与土壤水热参量的相关分析显示,多雪区积雪可以有效减少土壤中热量的流失,对土壤起到"保温"作用,积累和鼎盛阶段积雪与土壤温度、地表热通量同位相变化;积雪融水又可以增加土壤湿度,对土壤起到"增湿"作用,鼎盛阶段积雪与土壤含水量正相关,积雪日数对土壤湿度的影响要高于积雪深度。在多雪区,多雪年积累阶段、鼎盛阶段的土壤温度和土壤湿度也要高于少雪年。对整个高原而言,积雪偏多使得土壤冻结程度加大,土壤含水量减少。

青藏高原积雪变化对陆面能量水分传输过程有重要影响。本文采用RegCM4.7-CLM4.5模式模拟了高原及其周边地区31年的积雪过程,通过对模拟结果的EOF分解,发现高原积雪的时空变化主要呈现为高原主体与高原东北部反相、东西反相以及南北反相3种模态,方差贡献率分别为30.05%,14.86%和8.48%。合成分析显示,高原积雪异常中心与高原的主要积雪区较为一致,积雪深度与积雪日数均有减小的气候倾向,高原东南部的"三江源区"减小趋势最明显,高原中北部积雪有略微增加的趋势。积雪与土壤水热参量的相关分析显示,多雪区积雪可以有效减少土壤中热量的流失,对土壤起到"保温"作用,积累和鼎盛阶段积雪与土壤温度、地表热通量同位相变化;积雪融水又可以增加土壤湿度,对土壤起到"增湿"作用,鼎盛阶段积雪与土壤含水量正相关,积雪日数对土壤湿度的影响要高于积雪深度。在多雪区,多雪年积累阶段、鼎盛阶段的土壤温度和土壤湿度也要高于少雪年。对整个高原而言,积雪偏多使得土壤冻结程度加大,土壤含水量减少。