Sustainable development frontiers and divides: Transnational actors and US/China greenhouse gas emissions

Perpetuation of the South-North divide over climate change threatens to undermine the sustainability of the planet's vulnerable ecosystems. The current focus of international attention is on the USA and the PRC since both countries are in a position to negate or clinch the global warming mitigation efforts of the rest of the world community and because the two governments are primarily responsible for the entrenched global impasse over greenhouse gas (GHG) abatement. This contribution illustrates how transnational non-state actors, specifically Chinese American transmigrants, can make a difference in surmounting the US-China divide over GHG emissions, even in a time of state stalemate. Specific opportunities to shape sustainable development outcomes are explored by reference to energy efficiency, renewable energy, transportation, GHG capture, and public education projects. The discussion shows that, by teaming up with the NGOs, universities, foundations and firms engaged in or contemplating involvement in GHG emission mitigation projects in China, Chinese Americans from many walks of life who can manoeuvre skilfully along the climate change frontier occupy a potentially decisive position in terms of supporting sustainable development.     

A case study on project-level CO2 mitigation costs in industrialised countries: the Climate Cent Foundation in Switzerland

This paper analyses CO₂ emissions reduction costs based on project data from the Climate Cent Foundation (CCF), a climate policy instrument in Switzerland. Four conclusions are drawn. First, for the projects investigated, the CCF on average pays €63/ton. Due to the Kyoto Protocol, the CCF buys reductions only until 2012. This cut-off increases reported per ton reduction costs, as the additional lifetime project costs are set in relation to reductions only until 2012, rather than to reductions realised over the whole lifetime. Lifetime reduction costs are €45/t. Second, correlation between CCF's payments and lifetime reduction costs per ton is low. Projects with low per ton reduction costs should thus be identified based on lifetime per ton reduction costs. Third, the wide range of project costs per ton observed casts doubts on the widely used identification of the merit order of reduction measures based on average per ton costs for technology types. Finally, the CCF covers only a fraction of additional reduction costs. Decisions to take reduction efforts thus depend on additional, non-observable and/or non-economic motives. Any generalisation of results has to consider that this analysis is based on prospective costs of a sub-sample of projects in Switzerland.     

Evidence of aircraft activity impact on local air quality: A study in the context of uncommon airport operation

Wuhan Tianhe International Airport (WUH) was suspended to contain the spread of COVID-19, while Shanghai Hongqiao International Airport (SHA) saw a tremendous flight reduction. Closure of a major international airport is extremely rare and thus represents a unique opportunity to straightforwardly observe the impact of airport emissions on local air quality. In this study, a series of statistical tools were applied to analyze the variations in air pollutant levels in the vicinity of WUH and SHA. The results of bivariate polar plots show that airport SHA and WUH are a major source of nitrogen oxides. NO_x, NO₂ and NO diminished by 55.8%, 44.1%, 76.9%, and 40.4%, 33.3% and 59.4% during the COVID-19 lockdown compared to those in the same period of 2018 and 2019, under a reduction in aircraft activities by 58.6% and 61.4%. The concentration of NO₂, SO₂ and PM_2.5 decreased by 77.3%, 8.2%, 29.5%, right after the closure of airport WUH on 23 January 2020. The average concentrations of NO, NO₂ and NO_x scatter plots at downwind of SHA after the lockdown were 78.0%, 47.9%, 57.4% and 62.3%, 34.8%, 41.8% lower than those during the same period in 2018 and 2019. However, a significant increase in O₃ levels by 50.0% and 25.9% at WUH and SHA was observed, respectively. These results evidently show decreased nitrogen oxides concentrations in the airport vicinity due to reduced aircraft activities, while amplified O₃ pollution due to a lower titration by NO under strong reduction in NO_x emissions.     

巴黎协定下中国碳排放权省域分配及减排潜力评估研究

通过构建碳排放权区域分配模型完成了省域分配,在此基础上与当前各地实际碳排放量进行比对,明晰了各自初始空间余额;而后对碳排放权欠缺地区的碳减排潜力进行了综合评估。研究结果表明：（1）我国30个省区碳排放权分配存在较大差异,其中云南配额最高,占比高达10.53%;宁夏配额最少,占比仅为0.28%。（2）全国有14个省区碳排放权初始空间余额表现出盈余状态,根据成因差异可大致分为“低排放、高配额”“低排放、低配额”以及“高排放、高配额”等三种类型;其他16个地区均表现出一定程度的欠缺,结合数值差异可划分为以江苏等4地为代表的轻度欠缺地区,以天津等7地为代表的中度欠缺地区,以及以辽宁等5地为代表的重度欠缺地区。（3）浙江、天津、山东等3地目前所具备的碳减排潜力要明显高于其他地区,而各地区的碳减排潜力水平虽与其碳排放权欠缺量表现出了一定趋同性但并非完全一致。     

Economic Growth,Climate Change,Biodiversity Loss: Distributive Justice for the Global North and South

Abstract: Economic growth‐the increase in production and consumption of goods and services‐must be considered within its biophysical context. Economic growth is fueled by biophysical inputs and its outputs degrade ecological processes, such as the global climate system. Economic growth is currently the principal cause of increased climate change, and climate change is a primary mechanism of biodiversity loss. Therefore, economic growth is a prime catalyst of biodiversity loss. Because people desire economic growth for dissimilar reasons‐some for the increased accumulation of wealth, others for basic needs‐how we limit economic growth becomes an ethical problem. Principles of distributive justice can help construct an international climate‐change regime based on principles of equity. An equity‐based framework that caps economic growth in the most polluting economies will lessen human impact on biodiversity. When coupled with a cap‐and‐trade mechanism, the framework can also provide a powerful tool for redistribution of wealth. Such an equity‐based framework promises to be more inclusive and therefore more effective because it accounts for the disparate developmental conditions of the global north and south.     

Biotic homogenization and differentiation of plant communities in tropical and subtropical forests

Anthropogenic impacts on biodiversity can lead to biotic homogenization (BH) and biotic differentiation (BD). BH is a process of increasing similarity in community composition (including taxonomic, functional, and phylogenetic components), whereas BD is a process of decreasing similarity over space and time. Here, we conducted a systematic review of BH and BD in plant communities in tropical and subtropical forests to identify trends and knowledge gaps. Our bibliometric search in the Web of Science returned 1989 papers, of which 151 matched our criteria and were included in the analysis. The Neotropical region had the largest number of articles, and Brazil was the most represented country with 92 studies. Regarding the type of change, homogenization was more frequent than differentiation (noted in 69.6% of publications). The taxonomic diversity component was measured more often than functional and phylogenetic diversity components. Most studies (75.6%) assessed homogenization and differentiation based on a single observation in time; as opposed to few studies that monitored plant community over multiple years. Forest fragmentation was cited as the main determinant of homogenization and differentiation processes (57.2% of articles). Our results highlight the importance of evaluating community composition over time and more than taxonomic components (i.e., functional and phylogenetic) to advance understanding of homogenization and differentiation. Both processes were scale dependent and not mutually exclusive. As such, future research should consider differentiation as a potential transition phase to homogenization and that potential differences in both processes may depend on the spatial and temporal scale adopted. Understanding the complexity and causes of homogenization and differentiation is essential for biodiversity conservation in a world increasingly affected by anthropogenic disturbances.     

Landfill aeration in the framework of a reclamation project in Northern Italy

In situ aeration by means of the Airflow technology was proposed for landfill conditioning before landfill mining in the framework of a reclamation project in Northern Italy. A 1-year aeration project was carried out on part of the landfill with the objective of evaluating the effectiveness of the Airflow technology for landfill aerobization, the evolution of waste biological stability during aeration and the effects on leachate and biogas quality and emissions.The main outcomes of the 1-year aeration project are presented in the paper.The beneficial effect of the aeration on waste biological stability was clear (63% reduction of the respiration index); however, the effectiveness of aeration on the lower part of the landfill is questionable, due to the limited potential for air migration into the leachate saturated layers.During the 1-year in situ aeration project approx. 275 MgC were discharged from the landfill body with the extracted gas, corresponding to 4.6 gC/kgDM. However, due to the presence of anaerobic niches in the aerated landfill, approx. 46% of this amount was extracted as CH₄, which is higher than reported in other aeration projects. The O₂ conversion quota was lower than reported in other similar projects, mainly due to the higher air flow rates applied.The results obtained enabled valuable recommendations to be made for the subsequent application of the Airflow technology to the whole landfill.     

Do lower electricity storage costs reduce greenhouse gas emissions?

In the electricity sector, innovation in large-scale storage is anticipated to reduce costs and improve performance. The effect on greenhouse gas emissions of lower storage costs depends on the interactions between storage and the entire grid. The literature has disagreed on the role of storage in reducing emissions. In this paper we present a stylized model, which suggests that the effect of storage costs on emissions depends on the supply responsiveness of both fossil and renewable generators. Under common conditions in the United States, lower storage costs are more likely to reduce emissions when wind investment responds to equilibrium electricity prices and when solar investment does not. Simulations of a computational model of grid investment and operation confirm these intuitions. Moreover, because of its effect on coal and natural gas–fired supply responsiveness, introducing a carbon dioxide emissions price may increase the likelihood that lower storage costs reduce emissions.     

Natural and Anthropogenic Effects On Phytoplankton Primary Productivity in Mangroves

Spatial and temporal variations and the factors influencing primary production have been studied in three different mangrove waters (Pichavaram, Ennore Creek and Adyar Estuary) of South India characterised by different anthropogenic impacts. the gross primary productivity in the unpolluted Pichavaram mangrove was 113 g Cm^-2yr^-1 exhibiting natural variability with the environmental forcing factors. Human activities have elevated primary productivity in the Ennore Creek mangrove (157g Cm^-2yr^-1) primarily through the direct discharge of fertilizer effluents. By contrast, a combination of domestic and industrial effluent discharges into the Adyar Estuary mangrove has considerably reduced phytoplankton primary productivity 83g Cm^-2yr^-1 the Redfield N: P ratio varies from 0.96 N: 1P at Ennore Creek, 1.75N: 1P at Adyar Estuary to 15.2 N: 1P at Pichavaram mangroves. This suggests that the Pichavaram mangroves represent a well equilibrated ecosystem with N: P ratio close to steady-state values in contrast to the anthropogenically altered mangrove ecosystems studied. Results show a significant temporal variability in nutrient concentration in the three mangrove areas. Distinct differences in nutrient concentrations between the dry and the wet seasons have been observed.