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Purpose The purpose of this paper is to focus on global energy consumption using the economic growth nexus, the prevalent energy hypothesis at a global level and the impact of the main historical events assessed for the period from 1965 to 2015. Design/methodology/approach Given the confirmed presence of endogeneity and cointegration between energy consumption and economic growth, a vector error correction with structural dummies model was used. Furthermore, the impulse-response functions and variance decomposition were computed to evaluate the variables’ dynamics. Findings Bi-directional causality running from energy consumption to economic growth was found, both in the short and long-run, supporting the feedback hypothesis. It is proved that the 2008 crisis impacted on the global energy–growth nexus. Furthermore, there is evidence of the impact of the 1990s oil price shock on the nexus. Innovations in energy consumption have a positive impact on economic growth; however, this impact tends to be null in the long run. Practical implications The results suggest that at a global level, any energy policy should be carefully designed in order not to hamper economic growth. Countries should not remain indifferent to the policies that other countries might follow. Very few historical crises impacted on the global energy–growth nexus. Originality/value This paper offers a different approach to the study of the energy–growth nexus. The energy–growth nexus is analysed in the major macroeconomic aggregate. Global variables reveal their relevance as a benchmark in the energy–growth nexus. Furthermore, this paper arrives at some conclusions about how historical crises impact on global relationships.

The main objective of this research is to assess the impact of energy certificate ratings (EPCs) on the value per m2 of Portuguese housing sales. Data from 289 Portuguese municipalities between 2014 and 2019, analysed with a fixed effects panel and method of moments quantile regression, were used. EPCs with high energy efficiency ratings (e.g., A+, A, B, and B-) are used as a proxy for dwellings with “green” or “environmentally friendly” certificates. On the other hand, ratings with a low energy efficiency (e.g., C, D, E, and F) are used as a proxy for dwellings with “non-green” or “not environmentally friendly” certificates. The results support that EPCs associated with green housing increase the value per m2 of housing sales, and those associated with non-green housing decrease the sales value. It was also found that municipal GDP, tax/financial incentive policies for energy efficiency, and the number of completed dwellings in new constructions for family housing will increase sales value. On the other hand, credit agreements and completed reconstructions reduce sales value. Lastly, the results and outgrowths of this study will support the policymakers and governments in developing consistent policies and initiatives that promote the “green” or “eco-friendly” dwellings in Portugal or in similar economies.

Dissertação de Mestrado Integrado em Engenharia Química apresentada à Faculdade de Ciências e Tecnologia O estudo de novos tipos de energia e seus processos de produção tem sido encorajada devido ao elevado consumo energético global. A biomassa lenhocelulósica, devido à sua ubiquidade, tem sido alvo de extensos estudos com vista à produção de açúcares fermentáveis, produtos intermédios em diversos processos industriais, ou etanol. Adicionalmente, a nível industrial, são produzidas quantidades elevadas de lamas primárias que ainda podem ser reaproveitadas para a obtenção de produtos com valor acrescentado.Os processos biotecnológicos são processos de baixo custo energético e manutenção, o que os torna especialmente interessantes para aplicações e processos industriais. Dentro desses processos, encontra-se a hidrólise enzimática, um processo que recorre a enzimas, como a celulase, para transformar celulose em glucose, um açúcar fermentável, e a sacarificação e fermentação simultâneas, ou SSF, um processo que se foca na produção de bioetanol com recurso a leveduras, como a levedura Saccharomyces cerevisiae, que consomem os açúcares simples na sua atividade metabólica.O principal objetivo deste trabalho foi estudar a viabilidade das lamas primárias, provenientes de uma fábrica de papel kraft, às quais foram adicionadas fibras recicladas, para a produção direta de açúcares fermentáveis, através do processo de hidrólise enzimática e para a produção de bioetanol, através da metodologia SSF.Observou-se que a partir do processo de hidrólise enzimática, a concentração máxima de glucose obtida para as lamas primárias foi de 15,2 g L-1, resultando num rendimento teórico de hidrólise de 64,6%. Posteriormente estudou-se a aplicação de um tratamento alcalino com fosfato monopotássico, um agente que permite remover tintas, onde se obteve uma concentração de açúcares de 19,6 g L-1 ao fim de 24 h de reação.Na metodologia SSF obtiveram-se concentrações máximas de etanol de 6,2 g L-1 para as lamas primárias sem tratamento e de 6,9 g L-1 para as lamas primárias com tratamento alcalino, para uma consistência de 3% de massa de suspensão. No entanto, para as lamas com o tratamento mencionado anteriormente, e para uma consistência superior, 6%, obteve-se uma concentração máxima de etanol de 11,8 g L-1. The study of new types of energy and their production processes has been encouraged due to the high global energy consumption. Lignocellulosic biomass, due to its ubiquity, has been the subject of extensive studies considering the production of fermentable sugars, intermediate compounds in various chemical processes, and ethanol production. Additionally, at an industrial level, high quantities of sludge are produced that can still be used to generate products with greater value.Biotechnological processes are processes with a low energy and maintenance cost, which make them especially valued for industrial applications and processes. Within these processes, enzymatic hydrolysis is a process that uses enzymes, like cellulose, to transform cellulose into glucose, a fermentable sugar, and simultaneous saccharification and fermentation (SSF) is a process that produces bioethanol with the utilization of yeasts, like Saccharomyces cerevisiae, who consume simple sugars for their metabolism to produce ethanol.The primary objective of this work was to study the viability of the primary sludge, given by a kraft paper facility, to which were added recycled fibres, for the direct production of fermentable sugars, by the use of the enzymatic hydrolysis process, and for bioethanol production, by the use of the SSF methodology.The maximum sugar concentration observed in the enzymatic hydrolysis, for the primary non-treated sludge was 15,2 g L-1, which represents a theoretical hydrolysis yield of 64,6%. Meanwhile, by applying an alkaline treatment with the aid of monopotassium phosphate, an additive that allows ink removal, a maximum sugar concentration of 19,6 g L-1 was obtained, after 24 h.In the SSF methodology, the maximum ethanol concentration was 6,2 g L-1 for the non-treated primary sludge and 6,6 g L-1 for the treated sludge, both for a mass concentration of 3%. However, for a higher consistency, 6%, a maximum ethanol concentration of 11,8 g L-1 was obtained for the treated primary sludge.

This work addresses the problem of determining the most suitable sites for locating biogas plants using dairy manure as feedstock, specifically in the Entre-Douro-e-Minho Region in Portugal. A Multicriteria Spatial Decision Support System is developed to tackle this complex multicriteria decision-making problem, involving constraints and many environmental, economic, safety, and social factors. The approach followed combines the use of a Geographic Information System (GIS) to manage and process spatial information with the flexibility of Multicriteria Decision Aid (MCDA) to assess factual information (e.g. soil type, slope, infrastructures) with more subjective information (e.g. expert opinion). The MCDA method used is ELECTRE TRI, an outranking-type method that yields a classification of the possible alternatives. The results of the performed analysis show that the use of ELECTRE TRI is suitable to address real-world problems of land suitability, leading towards a flexible and integrated assessment.

The supply of raw materials is a global challenge to be addressed; themes such as “sustainability”, “responsibility”, and “eco-compatibility” represent the cornerstones for proceeding towards a “wise” management of georesources. According to the United Nations’ SDGs, the economic development of countries must go hand in hand with the improvement of their environmental, health, and social sustainability. From this perspective, the exploitation of georesources needs to be handled with an interdisciplinary approach that tackles not only the technical, economic, and environmental issues, but also the social, legislative, and human health ones. In recent years, Europe has promoted several cooperative projects aimed at boosting sustainability in the extractive industry. To achieve and guarantee concrete and truly sustainable mining, it is necessary to build and strengthen educational and training skills. With these objectives in mind, the first results of the EU–Africa SUGERE Erasmus+ project are presented here. The objects of the project are the implementation of Bachelor, Master, and doctoral curricula in geology and mining engineering and the promotion of socioeconomic development thanks to the training of experts who are able to cooperate and work in an interdisciplinary manner for a sustainable approach to local mine exploitation.

This research aims to answer two fundamental questions of the present time: First, what is the impact of the increasing complexity of economic structures and the production of complex goods on the environment? Second, can increasing export quality lead to the improvement of the environment? Given that the relationship of the ecological footprint and its determinants has been revealed to be nonlinear, the use of the quantile approach is supported. This finding led us to the central hypothesis of this research: economic complexity and export quality first deteriorate the ecological footprint (i.e., in lower quantiles), and the middle and higher quantiles contribute to reducing or mitigating environmental damage. The effect of economic complexity and export quality on the ecological footprint was researched using a two-step approach. First, club convergence was applied to identify the countries that follow a similar convergence path. After this, panel quantile regression was used to determine the explanatory power of economic complexity and export quality on the ecological footprint of 98 countries from 1990 to 2014. The club convergence revealed four convergent groups. Panel quantile regression was used because the relationship between the ecological footprint and its explanatory variables was shown to be nonlinear for the group of countries identified by the club convergence approach. GDP, nonrenewable energy consumption, and the population damage the environment. Urbanisation contributes to reducing the ecological footprint. Export quality and trade openness reduce the ecological footprint, but not at all quantiles. The effect of trade openness mitigating the ecological footprint is lost at the 90th quantile. Export quality becomes a reducer of the ecological footprint in the 50th quantile or above, and in the higher quantiles, its contribution to reducing the footprint is vast. Economic complexity aggravates the ecological footprint in low quantiles (10th), becomes non-statistically significant in the 25th quantile, and reduces the ecological footprint in higher quantiles. Policymakers must identify the impact of the ecological footprint and consider the demand and supply side of economics.

Abstract Affecting millions of Europeans, energy poverty is increasingly high on the political agenda. This paper compares space and water heating demand at household level in Germany and in the United Kingdom (UK) between 1991 and 2015. The elasticities of consumption of space and water heating with respect to price, income and heating degree days (HDD) are examined using non-parametric models. Domestic heating consumption is highly elastic with HDD in both countries and HDD elasticities are found to be higher in the UK. From a certain income threshold, heating demand decreases as income increases in German households whereas demand rises with higher incomes in the UK. High price elasticities indicate that UK households are very responsive to energy conservation measures, therefore implying that a pricing policy will effectively reduce heating consumption. However, in Germany, the impact of pricing policies is unclear. Thus, the most effective policy measure to decrease domestic heating consumption in Germany in the long-run should be one which targets improvements of building envelope performance levels.

The macroeconomic effect of the obesity epidemic on environmental degradation was examined for panel data from thirty-one European countries from 1991 to 2016. The quantile via moments model (QVM) was used to realize our empirical investigation. The empirical results indicate that the obesity epidemic, electricity consumption, and urbanisation encourage environmental degradation by increasing CO2 emissions, while economic growth decreases them. Moreover, we identify that the obesity epidemic raises the environmental degradation problem in three ways. First, the obesity epidemic is caused by the increased consumption of processed foods from multinational food corporations. The increase in food production will positively impact energy consumption from non-renewable energy sources. Second, obesity reduces physical and outdoor activities, increasing the intensive use of home appliances and motorized transportation and screen-viewing leisure activities, consequently increasing energy consumption from non-renewable energy sources. A third possible way can be related indirectly to economic growth, globalization, and urbanisation. This empirical investigation will contribute to the literature and for policymakers and governments. Therefore, this investigation will encourage the development of initiatives to mitigate the obesity problem in European countries and accelerate the energy transition process. Finally, this investigation will open a new topic in the literature regarding the correlation between the obesity epidemic and environmental degradation.