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Purpose This study aims to consider environmental sustainability, a global challenge under the preview of sustainable development goals, highlighting the significance of knowledge economy in attaining sustainable aggregate demand behavior globally. For this purpose, 155 countries that have data available from 1995 to 2021 were selected. The purpose of selecting these countries is to test the global responsibility of the knowledge economy to attain environmental sustainability. Design/methodology/approach Results are estimated with the help of panel quantile regression. The empirical existence of aggregate demand-based environmental Kuznets curve (EKC) was tested using non-linear tests. Moreover, principal component analysis has been incorporated to construct the knowledge economy index. Findings U-shaped aggregate demand-based EKC at global level is validated. However, environmental deterioration increases with an additional escalation after US$497.945m in aggregate demand. As a determinant, the knowledge economy is reducing CO2 emissions. The knowledge economy has played a significant role in global responsibility, shifting the EKC downward and extending the CO2 reduction phase for every selected country. Further, urbanization, energy intensity, financial development and trade openness significantly deteriorate the environmental quality. Originality/value This study contains the empirical existence of aggregate demand-based EKC. The role of the knowledge economy is examined through an index which is calculated by using four pillars of the knowledge economy (technology, innovations, education and institutions). This study is based on a combined panel of all the countries for which the data was available.

This paper develops a strategy for the continuing and improved supply of woodfuels to urban and industrial consumers in Sub-Sahara Africa. It argues that continued use of these fuels is not only a necessity, but is also in the best economic interest of most of the countries in this region. It shows that intensified and more orderly utilization of woodfuels can help to enhance, rather than impinge upon environmental parameters. Some examples are provided that illustrate how such strategies can be put into practice.

Abstract This paper formulates a model that assesses the economic and policy implications of the adoption and operation of microgrids. The recent climate agreement between the US and China as well as the historic Lima accord on climate change are prompting a massive demand in climate-friendly technologies. Given the increasing demand for electricity and the mounting costs of electricity supply associated with maximizing system performance through an optimal economic scheduling of microgrids, decision makers and policymakers are already facing the problem of sketching energy management strategies for localized operation and grid penetration. We employ a modified Benders' decomposition approach to explore the optimal scheduling of supply from different technology units in the microgrid in the face of supply and demand uncertainties. We guarantee that the power generated by the units meets systemic load while satisfying the primary operational and technological constraints. We implement our model in a quantitative numerical analysis where we investigate the operational regulation in the light of a public environmental policy. We extend prior research on this subject by uncovering a greater reliance on the grid under simultaneous uncertainties in demand and supply. We unlock a strategy for a proper mitigation of the effects of emissions. We find that carbon abatement policy can be used to motivate microgrids operators to invest in fuel cells and natural gas technologies when dealing with uncertainty.

A promising route to transition wastewater treatment facilities (WWTFs) from energy-consuming to net energy-positive is to retrofit existing facilities with process modifications, residual biosolid upcycling, and effluent thermal energy recovery. This study assesses the economics and life cycle environmental impacts of three proposed retrofits of WWTFs that consider thermochemical conversion technologies, namely, hydrothermal liquefaction, slow pyrolysis, and fast pyrolysis, along with advanced bioreactors. The results are in turn compared to the reference design, showing the retrofitting design with hydrothermal liquefaction, and an up-flow anaerobic sludge blanket has the highest net present value (NPV) of $177.36MM over a 20-year plant lifetime despite 15% higher annual production costs than the reference design. According to the ReCiPe method, chlorination is identified as the major contributor for most impact categories in all cases. There are several uncertainties embedded in the techno-economic analysis and life cycle assessment, including the discount rate, capital investment, sewer rate, and prices of main products; among which, the price of biochar presents the widest variation from $50 to $1900/t. Sensitivity analyses reveal that the variation of discount rates causes the most significant changes in NPVs. The impact of the biochar price is more pronounced in the slow pyrolysis-based pathway compared to the fast pyrolysis since biochar is the main product of slow pyrolysis.

Vehicles with hybrid drive systems, are increasingly more often being equipped with solutions that increase the drive systems efficiency. One of such solutions is to use an increased supply voltage for electric motors of such vehicles. The battery voltage is increased several times in the inverter system in order to increase the electrical power supplied to the electric motor. This article presents possible uses of such voltage amplification (called boost) in urban traffic conditions. The tests used the latest models of vehicles with hybrid drive systems equipped with the same drive units: Lexus NX 300h and Toyota RAV4 Hybrid. The study analyses the conditions of starting such a system and the characteristics of its operation. It has been shown that the amplification of the voltage powering the electrical machinery in both vehicles occurs at high torque values. The maximum voltage amplification–almost threefold (up to 650 V) allows a two-fold increase in the torque of the drive system.

Trace elements can have profound adverse effects on the health of people burning coal in homes or living near coal deposits, coal mines, and coal-burning power plants. Trace elements such as arsenic emitted from coal-burning power plants in Europe and Asia have been shown to cause severe health problems. Perhaps the most widespread health problems are caused by domestic coal combustion in developing countries where millions of people suffer from fluorosis and thousands from arsenism. Better knowledge of coal quality characteristics may help to reduce some of these health problems. For example, information on concentrations and distributions of potentially toxic elements in coal may help delineate areas of a coal deposit to be avoided. Information on the modes of occurrence of these elements and the textural relations of the minerals in coal may help to predict the behavior of the potentially toxic trace metals during coal cleaning, combustion, weathering, and leaching.

Xuanwei City (formerly known as Xuanwei County) locates in the northeastern of Yunnan Province and is rich in coal, iron, copper and other mines, especially the smoky (bituminous) coal. Unfortunately, the lung cancer morbidity and mortality rates in this region are among China's highest, with a clear upward trend from the mid-1970s to mid-2000s. In 2004-2005, the crude death rate of lung cancer was 91.3 per 100,000 in the whole Xuanwei City, while that for Laibin Town in this city was 241.14 per 100,000. The epidemiologic distribution (clustering patterns by population, time, and space) of lung cancer in Xuanwei has some special features, e.g., high incidence in rural areas, high incidence in females, and an early age peak in lung cancer deaths. The main factor that associates with a high rate of lung cancer incidence was found to be indoor air pollution caused by the indoor burning of smoky coal. To a certain extent, genetic defects are also associated with the high incidence of lung cancer in Xuanwei. Taken together, lung cancer in this smoky coal combustion region is a unique model for environmental factor-related human cancer, and the current studies indicate that abandoning the use of smoky coal is the key to diminish lung cancer morbidity and mortality.

SummaryThe German government has adopted a law that requires sewage plants to go beyond the recovery of phosphorus from wastewater and to promote recycling. We argue that there is no physical global short‐ or mid‐term phosphorus scarcity. However, we also argue that there are legitimate reasons for policies such as those of Germany, including: precaution as a way to ensure future generations’ long‐term supply security, promotion of technologies for closed‐loop economics in a promising stage of technology development, and decrease in the current supply risk with a new resource pool.

Abstract Like cities, many large national parks in the United States often include “urban” visitor and residential areas that mostly demand (rather than produce) energy and key urban materials. The U.S. National Park Service has committed to quantifying and reducing scopes 1 and 2 emissions by 35% and scope 3 emissions by 10% by 2020 for all parks. Current inventories however do not provide the specificity or granularity to evaluate solutions that address fundamental inefficiencies in these inventories. By quantifying and comparing the importance of different inventory sectors as well as upstream and downstream emissions in Yosemite National Park (YNP), this carbon footprint provides a case study and potential template for quantifying future emissions reductions, and for evaluating tradeoffs between them. Results indicate that visitor-related emissions comprise the largest fraction of the Yosemite carbon footprint, and that increases in annual visitation (3.43–3.90 million) coincide with and likely drive interannual increases in the magnitude of Yosemite′s extended inventory (126,000–130,000 t CO2e). Given this, it is recommended that “per visitor” efficiency be used as a metric to track progress. In this respect, YNP has annually decreased kilograms of GHG emissions per visitor from 36.58 (2008) to 32.90 (2011). We discuss opportunities for reducing this measure further.