Prospects for a saturation of humanity’s resource use? An analysis of material stocks and flows in nine world regions from 1900 to 2035

Material stocks in infrastructure, buildings and machinery shape current and future resource use and emissions. Analyses of specific countries and selected materials suggest that material stocks might saturate, which would be important for a more sustainable social metabolism. However, it is unclear to what extent the evidence holds for a wider range of stocks and flows, as well as for world regions or globally.We present an inflow-driven dynamic stock-flow model for 14 bulk materials, end-of-life outflows, recycling, and waste flows for nine world regions from 1900 to 2015, extended with trend scenarios until 2035. Material stocks are growing in all regions and show little signs of saturation yet. In 2015, China used half of global stock-building materials, overtook everyone in stock size around 2012 and grows its stock at ∼8%/year. The Industrialized regions, including the Former Soviet Union, are slowly expanding their high stock levels at ∼1%/year. Stocks in all other regions, inhabited by 60% of the world population, grow at ∼3–5%/year. Inequalities in per capita stocks between regions are large. Trend scenarios suggest potential absolute or per capita stock saturations in some of the industrialized regions, while all other regions are expected to continue high stock growth.Accumulated stocks drive future end-of-life materials and substantial maintenance and replacement requirements. Growing material stocks hamper a potential stabilization or reduction of resource use. Low stock levels in most world regions suggest a crucial window of opportunity for avoiding resource-intensive stock development. In the industrialized regions and especially China, stabilising and reducing resource use requires halting net stock expansion and transforming existing stocks. More materials- and energy-efficient and long-lived stocks which deliver high quality services, and improved reuse, repair and recycling of increasing end-of-life materials to close loops and actually replace virgin resources, are crucial for a more sustainable social metabolism.     

Hazardous waste from the global shipbreaking industry: Historical inventory and future pathways

Shipbreaking activities release hazardous wastes (namely, oil, asbestos, other landfillable wastes, and incinerable wastes) that harm both workers' health and the environment. However, an accurate and detailed emission inventory to support policy design of the greening reform remains lacking. By developing a framework that combines dynamic material flow model, global change assessment model and scenario analysis, this study carries out historical analysis and future projection of global ship scrap and pollutant emissions, based on ship scrap datasets. Our results show that shipbreaking sites have gradually shifted from more developed regions such as Taiwan, the European Union (EU), Japan, and Russia to the three less developed Southern Asian countries, Bangladesh, India, and Pakistan, in the past four decades. Waste emissions in these three countries have increased significantly by 6.5 times between 1990 and 2019. Although the volume of scrapped ships is expected to reach 75–95 million gross tons per year by 2050, the cumulative waste emissions from 2020 to 2050 will be reduced by 92% and 79% under the EU Convention and the Hong Kong Convention scenario, respectively. Lastly, policy implications such as how to mitigate the adverse impact of shipbreaking activities after the international conventions enter into force are comprehensively discussed.     

Carbon budget of managed forests in the Russian Federation in 1990–2050: Post-evaluation and forecasting

Considered are the contribution of managed forests in the Russian Federation to the climate change softening and the forecast of their carbon-depositing potential in the period till 2050 under different scenarios of the forest management. The sink of CO₂ to managed forests is estimated using the flow balance method. The CBM-CFS3 model worked out in the Canadian Forestry Service is used for predicting the carbon budget. It is found out that managed forests absorb 473.8 Mt of CO₂ per year. The carbon sink is caused by the reduction of the volume of the forest use and by the regeneration of cutover stands of previous years. Depending on the conditions of the forest use, by 2020 the CO₂ sink to managed forests will amount to 466–632 Mt/year and will be able to compensate from 21 to 29% of industrial emissions of greenhouse gases. The carbon absorption by managed forests will decrease to 105–235 Mt/year by 2050. To maintain and increase the carbon-depositing potential of managed forests, the Russian Federation needs the development of the system of purposeful activities on strengthening the protection against forest fires and on the intensification of forest reproduction.     

中国城市矿产开发对温室气体减排的影响分析

随着我国城市矿产开发的大力进行,其各方面的积极效益日益凸显。本文分析了我国城市矿产开发利用现状,并利用IPCC 提供的温室气体排放清单计算方法,对2011-2014 年我国废钢铁、废纸和废塑料的回收引起的CO₂ 和CH₄ 减排量进行统计分析。结果表明：2011-2014 年我国主要城市矿产开发的再生资源累计回收量为803.275 Mt,其中废钢铁、废纸和废塑料回收量最大,分别占2014 年回收总量的62.2%、18.0% 和8.2%;2011-2014 年废钢铁、废纸和废塑料回收引起的温室气体累计减排量分别为27.962 Mt CO₂-eq,954.695 Mt CO₂-eq 和22.502 Mt CO₂-eq,合计 1005.159 Mt CO₂-eq,温室气体减排效益明显。     

Exploring future copper demand,recycling and associated greenhouse gas emissions in the EU-28

Copper is widely used in modern technology, but declining ore grades and depletion of natural deposits have raised concerns regarding sustainable demand-supply balance in the long term. The vulnerability to primary copper supply restrictions amplifies for countries dependant on imports, notably many EU Member States. Recycling of post-consumer scrap can provide a valuable source of essential material to the European industry. However, a considerable fraction of collected and processed copper old scrap is exported, while the remaining fraction is either not recovered or lost due to nonfunctional recycling undermining the implementation of a circular economy. In this work, material flow analysis, regression analysis, and life cycle assessment are combined to explore the possible evolution of four scenarios of copper demand in Europe to year 2050 and the potentials for greenhouse gas emissions reduction under material circularity conditions.The results show that for three of the four scenarios, secondary production would not comply with the carbon dioxide emissions reduction target of 50% below 2000 levels neither in case of combined aggressive recycling, moderate decarbonization of electricity, and energy efficiency improvements. In particular, for the scenario that describes a “business as usual” approach, the modelled future domestic demand can only be met by increasing primary inputs and, despite strong efforts to improve recycling at end-of-life, the fraction of old scrap in total metal demand seems likely to achieve 65% at best. Should that scenario ensue, the GHG emissions embodied in EU copper demand might result in an emissions gap of more than 15 TgCO₂eq or about +260% the carbon dioxide reduction target. In contrast, the lowest environmental impacts are associated with a scenario emphasizing green technology and more equitable lifestyles. In that scenario, the secondary copper flows will gradually approach the expected demand, laying the foundation for achieving a circular economy with considerable potential for preserving natural capital and mitigating climate change. This possible future, however, requires dramatic changes in the current pattern of material production and consumption, as we discuss.     

Environmental benefits of circular economy approach to use of cobalt

Cobalt is an important critical material and a constituent of a broad range of products such as batteries, electronics, superalloys, and hard metals. Effective recycling of cobalt is considered one of the most pivotal processes in alleviating its criticality. In this paper, using the dynamic modelling of material, energy, and water flows in cobalt supply chain, we show that by 2050 around 25% of the total demand for cobalt could be supplied by recycling. Our results indicate that, compared to the primary production of cobalt, its recycling might lead to a reduction of energy consumption by 46% associated with the global cobalt supply chain and the corresponding fall in the use of water by 40%. In addition, recycling of cobalt is estimated to mitigate around 59% of the total emissions of greenhouse gases and 98% of the total emissions of sulfur oxides. Finally, we present the regionally distributed projections of cobalt-related energy and water use from 2020 to 2050.     

Production scenarios and the effect of soil degradation on long-term food security in China

Food security in China underlies the foundation of the livelihood and welfare for over one-fifth of the world's population. Soil degradation has an immense negative impact on the productive capacity of soils. We simulated the effect of soil degradation, which occurs in combination with increases in population size, urbanization rate, cropping intensity and decrease in cropland area, on long-term food security in China using a web-based land evaluation system. Our results predict that food crops may experience a 9% loss in productivity by 2030 if the soil continues to be degraded at the current rate (business-as-usual scenario, BAU). Productivity losses will increase to the unbearable level of 30% by 2050 should the soil be degraded at twice the present rate (double-degradation scenario, 2× SD). China's capacity for producing food from agricultural crops will be either adversely affected by the loss of cropland area (130, 113 and 107 million ha in 2005, 2030 and 2050, respectively) or favorably affected by agricultural intensification (in terms of the multi-cropping index at 120, 133 and 147% in 2005, 2030 and 2050, respectively). The loss of cropland is predicted to cause a 13–18% decrease in China's food production capacity by 2030–2050 relative to its 2005 level of 482 Mt, while agricultural intensification is predicted to cause an 11–23% increase. In total, China will be able to achieve a production level of 424 and 412 Mt by 2030 and 2050, respectively, under BAU, while this production will be only 386 and 339 Mt under 2× SD, respectively. In per capita terms, the relationship between food supply and demand will turn from an 18% surplus in 2005 to 3–5%, 14–18% and 22–32% deficits by 2030–2050 under the zero-degradation (0× SD), BAU and 2× SD scenarios, respectively. Our results show that the present-day production capacity will not sustain the long-term needs of a growing population under the current management level. Technical countermeasures and policy interventions need to be enacted today in order to avoid food insecurity tomorrow.     

Assessing phosphate rock depletion and phosphorus recycling options

We analyze global elemental phosphorus flows in 2009 for (1) mining to products, (2) animal and human manure flows, (3) crop harvests and animal production, (4) food production, (5) soil erosion, (6) and crop uptake. Informed by the flow assessment the potential and cost of phosphorus usage reduction and recycling measures are quantified, and fed into a constructed phosphorus supply-demand model with reserve assessment to assess the impact of these measures on phosphate rock resource availability. According to our results in 2009 globally 21.4 Mt elemental phosphorus from rock phosphate was consumed in products of which 17.6 Mt used as fertilizers, fully able to cover erosion losses and outputs in agriculture in aggregate, but insufficient from the perspective of bio-available phosphorus in soils. We find substantial scope for phosphorus use reduction, at potentially 6.9 Mt phosphorus, or 32% of 2009 phosphate rock supply. Another 6.1 Mt, or 28% can technologically be recycled from waterways and wastewater, but at a cost substantially above any foreseeable phosphate rock fertilizer price. The model results suggests phosphate rock reserves are sufficient to meet demand into the 22nd century, and can be extended well into the 23rd century with assessed use reduction and recycling measures.     

Assessment of changes in methane emissions from marsh ecosystems of northern Eurasia in the 21st century using regional climate model results

Changes in methane emissions into the atmosphere from terrestrial ecosystems are assessed with models for the European and Asian parts of Russia using the model unit of a methane cycle and calculations with a regional climate model. The calculations were performed for the present-day base period (1991–2000), for the middle (2041–2050), and late (2091–2100) 21st century using the SRES A2 anthropogenic emission scenario. The average emissions for the base period were equal to 8 Mt CH₄/year for the European part of Russia and 10 Mt CH₄/year for the Asian part. By the middle of the 21st century, they increased up to 11 and 13 Mt CH₄/year, and by the late 21st century, up to 14 and 17 Mt CH₄/year. These tendencies are associated with the increased warm period of the soil and dependence of the integral methane production on temperature. It is predicted that the maximum depth of freezing will lessen in the southern regions of the European and Asian parts of Russia by the late 21st century.     

Trans-Arctic shipping routes expanding faster than the model projections

Rapid declines in Arctic sea ice coverage over the past four decades have increased the commercial feasibility of trans-Arctic routes. However, the historical changes in navigability of trans-Arctic routes remain unclear, and projections by global circulation models (GCMs) contain large uncertainties since they cannot simulate long-term Arctic sea ice changes. In this study, we determined the changes in trans-Arctic routes from 1979 to 2019 by combining two harmonized high-quality daily sea ice products. We found that the trans-Arctic routes are becoming navigable much faster than projected by the GCMs. The navigation season for open water (OW) vessels along the Northeast Passage (NEP) has lengthened from occasionally navigable in the 1980 s to 92 ± 15 days in the 2010 s. In contrast, previous GCM projections have suggested that navigability would not be achieved until the mid-21st century. The 90-day safety shipping area for OW vessels expanded by 35% during 1979–2018, reaching 8.28 million km² in 2018, indicating an increasing rate of 0.08 ± 0.01 million km² per year. The shortest trans-Arctic routes were also shifted further north than the model projections. Regular ships have been able to safely travel north along the islands in the NEP and transit through the M’Clure Strait in the Canadian Arctic Archipelago during the 2010 s, while previous studies have projected that this would not be feasible until the mid-21st century. We also found that the improved navigability of trans-Arctic routes enables commercial ships to transport approximately 33–66% (at the same load factor) more goods from East Asia to Europe during the Arctic shipping season than by the traditional Suez Canal route. These findings highlight the need for aggressive actions to develop mandatory rules that promote navigation safety and strengthen environmental protection in the Arctic.     

碳中和愿景下的污水处理厂温室气体排放情景模拟研究

污水处理厂运行过程中大量释放甲烷(CH4)和氧化亚氮(N2O),是重要的人为温室气体排放源.基于2005—2015年统计资料和IPCC核算方法,估算了2005—2015年中国生活污水处理厂CH4和N2O排放,分析了其排放特征和影响因素;依据碳中和愿景设定3种减排情景(低减排、中减排和高减排),并预估了2020—2050...     

Weather routing in long-distance Mediterranean routes

The selection of ship routes based on modern weather forecasting is a mean of computing optimum shipping routes thereby increasing safety and comfort at sea, cutting down on transit time, and reducing fuel consumption. Further empirical research in the effectiveness of modern weather routing applications is required especially in applications concerning shorter routes in enclosed seas of limited geographical extent such as the Mediterranean Sea. The present study used two climatological simulations to test this state-of-the-art approach to ship routing. Simulations represented two theoretical routes: (1) a route between Italy and Greece and (2) a route between Cyprus and Italy. Both routes were analyzed across varying simulated climatic conditions and the results were compared with those of control routes. Furthermore, results were analyzed in terms of passenger and crew comfort, bunker consumption by ships, and time of crossing. The first simulation showed that weather routing would improve ship performance on 37% of days while the second simulation revealed that weather routing would support ship captains virtually all the time.     

Approaching moisture recycling governance

The spatial and temporal dynamics of water resources are a continuous challenge for effective and sustainable national and international governance. The watershed is the most common spatial unit in water resources governance, which typically includes only surface and groundwater. However, recent advances in hydrology have revealed ‘atmospheric watersheds’ – otherwise known as precipitationsheds. Water flowing within a precipitationshed may be modified by land-use change in one location, while the effect of this modification could be felt in a different province, country, or continent. Despite an upwind country's ability to change a downwind country's rainfall through changes in land-use or land management, the major legal and institutional implications of changes in atmospheric moisture flows have remained unexplored. Here we explore potential ways to approach what we denote as moisture recycling governance. We first identify a set of international study regions, and then develop a typology of moisture recycling relationships within these regions ranging from bilateral moisture exchange to more complex networks. This enables us to classify different types of possible governance principles and relate those to existing land and water governance frameworks and management practices. The complexity of moisture recycling means institutional fit will be difficult to generalize for all moisture recycling relationships, but our typology allows the identification of characteristics that make effective governance of these normally ignored water flows more tenable.     

A quantitative evaluation of surface-based observations of oceanic cloudiness

Observations of cloud amount and cloud character are made regularly at ocean locations worldwide, predominantly from civilian ships but reports are also obtained from military vessels, research and rescue ships, voyaging boats, and oil and other drilling platforms. There is a long historical record of these observations of oceanic cloudiness but, to date, very few attempts have been made to try to establish the verity of this cloud climatology. All-sky camera photographs were obtained from voyages of research vessels in the summer of 1986 in the Atlantic and Indian oceans and the Mediterranean Sea. Detailed analysis of this data base generally validates the cloud observations made by the ships officers. Agreement between the synoptic observation and the image analysis was usually within one okta (eighth) of sky cover for total cloud amount. On the other hand the photographs reveal a considerable temporal heterogeneity in oceanic cloud amount. It is not clear whether the synoptic reports sample cloud amount adequately. The all-sky photographs underline the difficulty of identifying cirrus cloud. Occasionally ship reports miss clearly identifiable high cloud.     

The effect of climate change on hydrological regimes in Europe: a continental perspective

This paper outlines the effects of climate change by the 2050s on hydrological regimes at the continental scale in Europe, at a spatial resolution of 0.5×0.5°. Hydrological regimes are simulated using a macro-scale hydrological model, operating at a daily time step, and four climate change scenarios are used. There are differences between the four scenarios, but each indicates a general reduction in annual runoff in southern Europe (south of around 50°N), and an increase in the north. In maritime areas there is little difference in the timing of flows, but the range through the year tends to increase with lower flows during summer. The most significant changes in flow regime, however, occur where snowfall becomes less important due to higher temperatures, and therefore both winter runoff increases and spring flow decreases: these changes occur across a large part of eastern Europe. In western maritime Europe low flows reduce, but further east minimum flows will increase as flows during the present low flow season – winter – rise. “Drought” was indexed as the maximum total deficit volume below the flow exceeded 95% of the time: this was found to increase in intensity across most of western Europe, but decrease in the east and north. The study attempted to quantify several sources of uncertainty, and showed that the effects of model uncertainty on the estimated change in runoff were generally small compared to the differences between scenarios and the assumed change in global temperature by 2050.     

Global climate change and potential effects on Pacific salmonids in freshwater ecosystems of southeast Alaska

General circulation models predict increases in air temperatures from 1°C to 5°C as atmospheric CO₂ continues to rise during the next 100 years. Thermal regimes in freshwater ecosystems will change as air temperatures increase regionally. As air temperatures increase, the distribution and intensity of precipitation will change which will in turn alter freshwater hydrology. Low elevation floodplains and wetlands will flood as continental ice sheets melt, increasing sea-levels. Although anadromous salmonids exist over a wide range of climatic conditions along the Pacific coast, individual stocks have adapted life history strategies—time of emergence, run timing, and residence time in freshwater—that are often unique to regions and watersheds. The response of anadromous salmonids will differ among species depending on their life cycle in freshwater. For pink and chum salmon that migrate to the ocean shortly after they emerge from the gravel, higher temperatures during spawning and incubation may result in earlier entry into the ocean when food resources are low. Shifts in thermal regimes in lakes will change trophic conditions that will affect juvenile sockeye salmon growth and survival. Decreased summer stream flows and higher water temperatures will affect growth and survival of juvenile coho salmon. Rising sea-levels will inundate low elevation spawning areas for pink salmon and floodplain rearing habitats for juvenile coho salmon. Rapid changes in climatic conditions may not extirpate anadromous salmonids in the region, but they will impose greater stress on many stocks that are adapted to present climatic conditions. Survival of sustainable populations will depend on the existing genetic diversity within and among stocks, conservative harvest management, and habitat conservation.     

长江航运气象预报预警服务系统设计与应用

为面向长江航运开展可视化气象保障服务,本文设计了天气通航等级来表征天气对航运的影响,给出了应用沿江气象实况监测、网格预报、服务预警信息,计算航运调度管理和船舶行程规划两种服务场景下天气通航等级的具体算法和应用天气通航等级开展智能航运气象服务的方法,介绍了基于天气通航等级的长江航运气象预报预警服务系统的总体设计、主要产品、系统功能和主要特点,并结合航运气象服务发展,探讨了系统未来的改进方向。     

Food security or economic profitability? Projecting the effects of climate and socioeconomic changes on global skipjack tuna fisheries under three management strategies

We investigate the interactions between anthropogenic climate change, socioeconomic developments and tuna fishery management strategies. For this purpose, we use the APECOSM-E model to map the effects of climate change and commercial fishing on the distribution of skipjack tuna biomass in the three oceans, combined with a new bioeconomic module representing the rent or profit of skipjack fisheries. For forcing, we use Representative Concentration Pathway (RCP) 8.5, the highest emission scenario for greenhouse gas concentrations presented in the IPCC’s Fifth Assessment Report (AR5), and the IPCC Socioeconomic Shared Pathway (SSP) 3, which is characterized by low economic development and a strong increase in the world population. We first investigate the impact of climate change on regional skipjack abundance, catches and profits in three oceans (Atlantic, Indian and Pacific) in 2010, 2050 and 2095. We then study the effects of three management strategies (maximum sustainable yield or MSY, maximum economic yield or MEY, and zero rent or ZR) on the future distribution of fishing fleets between oceans and on global economic rent.Our model projections for 2050 and 2095 show an increase in global skipjack biomass compared to 2010 and major changes in its distribution, impacting local and regional fishing efforts. The Pacific Ocean will continue to dominate the skipjack market.In our modeling of management strategies, the currently predominant MSY strategy would have been unprofitable in 2010, due to a decreased catch per unit effort (CPUE). In the future, however, technological developments should increase fishing efficiency and make MSY profitable.In all the scenarios, a MEY strategy is more profitable than MSY but leads to the lowest catches and the highest prices. This raises ethical questions in a world where food security may become a top priority.In the scenarios where MSY generates an economic loss (e.g. 2010), a ZR strategy allows global stocks to be exploited at high but still profitable levels. Conversely, in the scenarios where MSY is profitable, (e.g. 2095) ZR leads to overfishing and smaller global catches.We conclude that the most appropriate management strategy at any time is likely to change as environmental and socioeconomic conditions evolve. The decision to follow one or other strategy is a complex one that must be regularly reviewed and updated.     

IPCC AR6报告解读:强化技术和管理创新的交通运输部门减碳路径北大核心CSCD

IPCC第六次评估报告第三工作组报告交通运输章评估了该行业温室气体的减缓措施和转型路径。1990年以来,全球交通运输部门温室气体排放量一直增长,2019年已经成为全球第四大排放源,仅次于电力、工业以及农业、林业和其他土地利用(AFOLU)部门,其增长速度超过其他最终用途行业。报告强调了交通减排的重要性,主要的减排措施包括三方面:首先是减少需求,其次是对陆路交通部门进行脱碳,再次是对重型的水运和航空运输等进行脱碳。评估的多种燃料和动力技术处于不同的商业化水平,它们未来应用时间节点和规模各有不同。对于陆路交通来说,需要继续推进电气化;对于水运和航空来说需要进一步应用低碳技术,并优化国际管理机制;从中长期来看,所有部门都需要强调运输服务需求管理和运输效率的提升。情景相关的文献评述分析表明,全球温升目标要求全经济部门采取减排措施,特别是交通电气化的减排潜力在很大程度上取决于电力部门的脱碳。如果不采取减缓措施,交通运输部门排放在2050年可能增长65%(相对2010年);如果成功实施减缓战略,该部门的排放量将减少68%,这也与全球1.5℃温升目标要求相一致。关于这些减缓措施的分析和判断,对我国交通运输部门实现碳中和与碳达峰具有重要的参考意义。     

New evidence of orographic precipitation suppression by aerosols in central China

The correlation between light precipitation events and visibility at Mt. Hua, (Shannxi Province, China) and at the surrounding plains stations was analyzed. Trends and changes in visibility, precipitation, the precipitation difference between Mt. Hua and the plains stations (De) and wind speed over the study area during the years 1980–2009 were also investigated. The significant positive correlation between visibility and light precipitation throughout the study period indicates that light precipitation events, notably orographic precipitation, are suppressed by aerosol pollution in this region. The trend of increasing air pollution aerosols since 1980, represented by visibility at Mt. Hua, ended in 2002 with a decreasing trend observed in more recent years. These changes were mirrored by corresponding changes in De. However, the total precipitation trends at Mt. Hua and the plains stations are consistent in both frequency and amount during the two periods, suggesting that the suppressive effect of pollution aerosols on light and moderate precipitation is the most likely cause for the changes in orographic precipitation at Mt. Hua during this time. The analysis of wind strength suggests that the increase in winds at Mt. Hua is highly related to the aerosol radiative effects; this increase of mountain winds is therefore a potential cause for the reduction in precipitation at Mt. Hua. This research provides further support for the hypothesis that aerosol microphysical effects can reduce orographic precipitation and suggests that aerosol radiative effects might act to suppress orographic precipitation through changes in wind speed.