Earth vitality:An integrated framework for tracking Earth sustainability

The Anthropocene era is characterized by the escalating impact of human activities on the environment,as well as the increasingly complex interactions among various components of the Earth system.These factors greatly affect the Earth's evolutionary trajectory.Despite notable strides in sustainable development practices worldwide,it remains unclear to what extent we have achieved Earth sustainability.Consequently,there is a pressing need to enhance conceptual and methodological frameworks to measure sustainability progress accurately.To address this need,we developed an Earth Vitality Framework that aids in tracking the Earth sustainability progress by considering interactions between spheres,recognizing the equal relationship between humans and nature,and presenting a threshold scheme for all measures.We applied this framework at global and national scales to demonstrate its usefulness.Our findings reveal that the current Earth Vitality Index is 63.74,indicating that the Earth is in a"weak"vitality.Irrational social institutions,unsatisfactory life experiences and the poor state of the biosphere and hydrosphere have remarkably affected the Earth vitality.Additionally,inequality exists between high-income and low-income countries.Although most of the former exhibit poor human-nature interaction,all of them enjoy good human well-being,while the opposite is true for the latter.Finally,we summarize the challenges and possible options for enhancing the Earth vitality in terms of coping with spillover effects,tipping cascades,feedback,and heterogeneity.

Risk assessment of transnational oil investment in Central Asia using a fuzzy comprehensive evaluation method

Central Asia(including five countries:Kazakhstan,Kyrgyzstan,Turkmenistan,Uzbekistan,and Tajikistan)is rich in oil reserves and has become one of the most important target regions for global oil investment.The construction of the Silk Road Economic Belt has prompted Central Asia to look outwards for more collaborations in the oil industry.China's need for oil investment in Central Asia has also increased significantly.This research established a comprehensive index system for assessing the risks of transnational oil investment in Central Asia.The system incorporated political,regulatory,economic,social,and infrastructural indices.Based on the Delphi method and fuzzy comprehension evaluation method,we qualitatively and quantitatively assessed and analyzed the risks of transnational oil investment in Central Asia.The results indicate that the risk score for regulatory risk was highest with the value of 6.1670,indicating a high risk level in transnational oil investment,followed by economic,social,political,and infrastructural risk indices.Of the 18 secondary risk indices calculated,there were seven indices with the probability of high risk occurrence exceeded 30.0%and the descending order was as follows:establishment of mining rights;host country intervention in operations;taxing system;stability of regulations;war and turmoil;labor capital;and ethnic,cultural,and religious differences.These seven critical risks should be watched closely and avoided during transnational oil investment in Central Asia.This study provides a comprehensive understanding of the potential risks of investing oil in Central Asia.The findings demonstrate the causes of these risks and provide a scientific basis for reasonably avoiding oil investment risk and improving investment benefits for both host and investing countries.

Spatial-temporal patterns and evolution of carbon storage in China's terrestrial ecosystems from 1980 to 2020

Analyzing the changes in carbon storage in terrestrial ecosystems caused by land use changes is a crucial part of exploring the carbon cycle. In addition, enhancing carbon storage in terrestrial ecosystems is an effective and environmentally friendly measure to sequester anthropogenic carbon emissions, which is significant for achieving carbon neutrality and curbing global climate change. This paper uses land use data and carbon density tables with the In VEST model to obtain a carbon storage distribution map of China. It further applies land use response elasticity coefficients, Theil index multi-stage nested decomposition, and spatial autocorrelation analysis to examine the spatial-temporal patterns, causes of changes, and evolution characteristics of carbon storage in terrestrial ecosystems from 1980 to 2020. The results show that the temporal changes in China's carbon storage generally present an inverted S-curve, with an initial rapid decline followed by a slower decrease. Spatially, it features high levels in the northeast, low levels in the northwest, and a uniform distribution in the central and southern regions.The disturbance of land use type changes on terrestrial ecosystem carbon storage has been effectively mitigated. The significant reduction in grassland area in the Southwest region is the main source of carbon storage loss during the study period, and the encroachment of construction land on arable land in large urban agglomerations is one of the important causes of carbon storage loss. The Theil index multi-stage nested decomposition results indicate that the overall difference in carbon storage in China has decreased, while differences among cities within provinces and among counties within cities have increased. The influence of natural factors on the distribution of carbon storage is weakening, whereas the impact of human activities is becoming more profound, enhancing its influence on the spatial distribution of carbon storage in China. From 1980 to 2000, the carbon density in coastal metropolises generally showed a declining trend. From 2000 to 2020, the carbon density in the central urban areas of eastern coastal city clusters gradually showed an upward trend and continued to expand outward, revealing to some extent the“Environmental Kuznets Curve” characteristic in the development process of urban carbon storage. Therefore, in future ecological construction, the government should fully consider the impact of land management planning on carbon storage in different regions, promote the efficient use and standardized management of land, and strive to cross the “Environmental Kuznets Curve” inflection point of carbon storage as soon as possible.

国际贸易对环境脆弱性的影响

Owing to the harsh natural environment and unsustainable production system,environmental vulnerability differs substantially among and within regions^([1]).Over the past 20 years,the most environmentally vulnerable countries lost over half of their economic growth potential^([2]).International trade is a double-edged sword for environmental vulnerability.On the one hand,production occurs beyond countries’borders while associated environmental impacts are displaced away from the location of consumption.

“一带一路”沿线国家可持续发展综合评估及分区管控

联合国《2030年可持续发展议程》为全球实现社会-经济-环境协调发展提供了行动方案.通过构建多区域投入产出模型,测算了"一带一路"沿线65个国家的环境足迹,并与基于行星边界分配的承载端相结合,评估了各国在水资源利用、土地利用、碳排放、氮排放和磷排放方面的环境可持续性.进一步测度了各国的可持续发展目标(sustainable development goals,SDGs)实现进程,运用空间计量模型揭示了环境可持续性与社会经济SDGs之间的权衡与协同关系,在此基础上对"一带一路"地区的可持续发展分区管控策略进行了探讨.结果表明:多数国家的土地、碳、氮、磷足迹均已超过其对应环境边界,"一带一路"地区的环境可持续性呈现显著的空间自相关性;减贫、健康等涉及人类基本生存问题的SDGs实现程度较高,而经济增长、可持续生产和消费等SDGs则亟待突破;与环境可持续性呈现协同关系的SDGs应作为社会经济发展的优先目标,而呈权衡关系的SDGs则要防范其实现过程中可能产生的生态环境风险;根据各国的环境可持续性和SDGs实现情况,识别了绿色先行、重点开发、绿色转型和风险防控四类可持续发展分区类型.

Spatiotemporal characteristics of the expansion of an urban agglomeration and its effect on the eco-environment: Case study on the northern slope of the Tianshan Mountains

Urban agglomerations, which are highly integrated urban groups, form during the advanced stages of industrialization and urban development. The urban agglomeration on the northern slope of the Tianshan Mountains is one of the 19 urban agglomerations promoted by China’s 13th Five-Year Plan and a key area of urbanization in Xinjiang. Based on remote sensing data, we analyzed the expansion of construction land in the urban agglomeration on the northern slope of the Tianshan Mountains and its effect on ecological value in 1980–2015. The results show that the expansion of construction land significantly affected ecological value in the study area over the past 35 years. Among land use types, grassland was the dominant contributor to changes in ecological value;its contribution rate reached 66.27% with an interannual variation of only 5%. The contribution rate of urban and rural residential land along with industrial and mining lands was very low(0.82%), while the interannual variation was large(86%). The area of construction land in the urban agglomeration expanded from 1,067 to 2,586 km^2, and the conversions of different land use types had different effects on ecological value. Among land use types, the conversions of lowcoverage grassland and dry land made the largest contributions to changes in ecological value. During the study period, a total of 1,685 km^2 of ecological land, 69.91% of which belonged to cultivated land and grassland, was converted into construction land.A total area of 1,082 km^2 of dry land and low-coverage grassland was converted into construction land, accounting for 64.21% of the total ecological land that was converted into construction land. In 2000–2015, the area of urban construction land increased significantly along with the proportion of unused land, including gobi(172 km^2), bare land(65 km^2), and salt-affected land(65 km^2), being converted into construction land. In contrast, the area of construction land that was converted into ecological land was less than 166 km^2. The areas with the largest expansions of construction land were concentrated in Urumqi, Karamay,and Changji, where the areas of construction land increased by 399, 186, and 126 km^2, respectively. The areas with the most rapid expansions in construction land were concentrated in Kuytun, Toksun, and Usu. The environmental effects of construction land expansion and land use change were more positive in the late stage of urban agglomeration(2000–2015) compared to in the early stage(1980–2000). Kuytun City, Shihezi City, and Wujiaqu City showed large changes in ecological value caused by the expansion of construction land, whereas the changes in ecological value in the 14 other cities were relatively small, and the expansion of construction land slowed in 2000–2015 compared to in 1980–2000. In the future, further development of the urban agglomeration on the northern slope of the Tianshan Mountains should fully consider the sensitivity and carrying capacity of the vulnerable ecological environment in this area. Population growth and industrial development in the urban agglomeration should be controlled based on the available water resources and ecological capacity to reduce the pressure on the environment and ensure sustainable development.

Quantitative simulation and verification of upgrade law of sustainable development in Beijing-Tianjin-Hebei urban agglomeration

The natural formation and development of urban agglomerations is a process in which core cities continue to unite their neighboring cities to enhance sustainability for their own sustainable development.The upgrade mechanism of sustainable development urban agglomeration is a nonlinear composite upgrade curve that is a function of time,increasing with the number of cities.In this paper,the sustainable upgrade function curve,upgrade rate,and upgrade speed of urban agglomerations were solved using a geometrical derivation,and the index system for measuring the upgrade capability of sustainable development of urban agglomerations was established.The dynamic change in economic sustainable upgrade capability,social sustainable upgrade capability,environmental sustainable upgrade capability,and comprehensive sustainable upgrade capability of a Beijing-Tianjin-Hebei urban agglomeration from 2000 to 2015 was measured by technique for order preference by similarity to an ideal solution and a grey correlation method,and a comprehensive,intercity unite strength model and a unite threshold calculation method for urban agglomerations were established.The research shows that the economic sustainable upgrade capability,social sustainable upgrade capability,environmental sustainable upgrade capability,and comprehensive sustainable upgrade capability of the Beijing-Tianjin-Hebei urban agglomeration all show a wave-like rising trend.The average annual upgrade speeds during 2000-2015 are,respectively,2.4%.1.67%,1.1%,and 1.74%,with the intercity comprehensive unite strength of urban agglomerations maintaining a general increase;but there is a limit to the joint threshold.From 2000 to 2015,as the core city of the Beijing-Tianjin-Hebei urban agglomeration,Beijing,to enhance its sustainable upgrade capability,jointly developed with Tianjin,Langfang,and Baoding before 2000,Tangshan in 2002,Cangzhou in 2009,Zhangjiakou and Shijiazhuang in 2012,and Chengde in 2014.By 2015,the comprehensive unite strength between Beijing and four cities(Handan,Qinhuangdao,Hengshui,and Xingtai) was still lower than the unite threshold of 6.14.These four cities are relatively far from Beijing,and offer no substantial contribution to the sustainable upgrade capability of Beijing.Through multiple fittings of the upgrade curve using the long-term sequence index of the comprehensive sustainable upgrade capability of Beijing(the core city of the Beijing-Tianjin-Hebei urban agglomeration) from 2000 to 2015,it was found that the simulated curve of the comprehensive sustainable upgrade function of the agglomeration was very similar to the curve of the comprehensive sustainable upgrade capability,which indicates that the simulation results are satisfactory.The future comprehensive sustainable upgrade capability of the agglomeration can be analyzed and predicted by the comprehensive sustainable upgrade function model.This study provides quantitative decision-supporting evidence for promoting the coordinated development of the Beijing-TianjinHebei urban agglomeration and provides theoretical guidance and algorithms for determining the number of cities joined with the sustainable development of national urban agglomerations.

Evolutionary characteristics and driving factors of carbon emission performance at the city level in China

To achieve carbon peak targets,realize carbon neutrality vision,and tackle global climate change,China must improve the carbon emission performance at the city level.Based on the carbon emission performance of 191 prefecture-level cities in China from 1997 to 2017,this paper analyses the evolution characteristics of urban carbon emission performance from three aspects:the overall spatial and temporal evolution,the differences according to both region and city size,and the differences among clusters categorized by carbon emission performance at the city level.This paper also reveals the impact of the social and economic transition on China’s carbon emission performance.The results show that:(1)The overall level of carbon emission performance of Chinese cities is low,and there is a downward trend during the study period.The differences in carbon emission performance among cities are convergent,but there is a wide gap between high and low values.(2)The carbon emission performance of cities in eastern coastal areas is higher than that in non-coastal areas cities.Large urban agglomerations and economically developed regions,such as provincial capitals,are the agglomeration areas of high urban carbon emission performance values.(3)The carbon emission performance level of cities with similar sizes will converge.At the same time,such changes will enhance the differences among carbon emission performances at the city level within the same region.(4)Cities that belong to high urban carbon emission performance clusters are mainly distributed in the eastern region.Such cities are classified into large cities,supercities,and megacities.Compared with low urban carbon emission performance clusters,cities in high urban carbon emission performance clusters show a higher proportion in the medium-high level and high level of carbon emission performance.Moreover,cities in high urban carbon emission performance clusters are more likely to improve their urban carbon emission performance.(5)The economic agglomeration effect,industrial structure adjustment and carbon intensity reduction have a significant impact on improving urban carbon emission performance.Population agglomeration has an incremental effect,and the anticipated benefits of environmental regulation have yet to be fully realized.The impacts of different clusters and different regions are variable.Finally,this paper advances policy enlightenment according to its research findings.