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Background: Currently, most of the world's population lives in cities, and the rapid urbanization of the population is driving increases in the demand for products, goods and services. To effectively design policies for urban sustainability, it is important to understand the trends of flows in energy and materials as they enter and leave a city. This knowledge is essential for determining the key elements characterizing future urban growth and addressing future supply challenges. Methods: This paper presents an analysis of the energy and material flows in the city of Bogotá over the time span from 2001 to 2017. Urban flows are also characterized in terms of their temporal evolution with respect to population growth to compare and identify the changes in the main input flows, wealth production, emissions and waste in the city. Results: The results of the analysis are then compared with those for other selected large urban agglomerations in Latin America and worldwide to highlight similarities and make inferences. The results show that in Bogotá, there was a decrease in some of the material flows, such as the consumption of water and the generation of discharge, in recent years, while there was an increase in the consumption of energy and cement and in the production of CO2 emissions and construction materials. Solid waste production remained relatively stable. With respect to the other large cities considered, we observe that the 10-year growth rates of the flows with respect to population growth are lower in Bogotá, particularly when compared with the other urban agglomerations in Latin America. Conclusions: The findings of this study are important for advancing characterizations of the trends of material and energy flows in cities, and they contribute to the establishment of a benchmark that allows for the definition and evaluation of the different impacts of public policy while promoting the sustainability of Bogotá in the coming decades. [ABSTRACT FROM AUTHOR]

Developing energy solutions that positively impact issues related to economic growth, the environment and social equity in cities is important. A better understanding of urban energy use, particularly in developing countries, can strengthen energy security, climate change mitigation and local pollution abatement. This study seeks to evaluate the trends in energy use and CO 2 emissions in Bogotá by determining energy flows through input and output analyses. The study establishes a relationship between energy and sustainable development by applying correlation analyses. Bogotá consumes 24% of the electricity produced in the country, generates 96010.1 TJ of the gross energy, and emits CO 2 , NOx and CO (carbon monoxide). Correlation analyses indicate a strong and direct relationship between energy, economic variables and social variables, with the majority of the correlation coefficients exceeding 0.8. Strong positive correlations are particularly observed between energy consumption, the gross domestic product, the human development index and CO 2 emissions. Energy per capita and CO 2 emissions per capita also strongly correlate with the human development index and GINI coefficients. These results demonstrate that energy increasingly influences the development, economic growth and welfare of the city population. Thus, formulating strategies that will improve energy use in cities is important. [ABSTRACT FROM AUTHOR]

Abstract: The urbanisation process has exceeded the traditional pace of human settlement and is moving towards the formation of large urban regions in response to an increasing demand for services and environmental goods, combined with increasing production of waste and emissions. Therefore, it is fundamental to determine resource flows into cities, especially in developing countries, as well as the transformations that occur and the outputs that are produced, such as products, services and wastes. In this study, we apply urban material flow analysis, which determines the flows of inputs (water, energy, food and others) and outputs (wastewater, air pollution, wastes and others) to the city of Bogotá, Colombia to determine the relationship between demand for resources and the environmental impact of outputs. Quantitative and qualitative data for Bogotá are used to assess and compare the material and energy flow trends for this city. The results indicate that in this city, inputs and outputs are directly and linearly related. Consumption of energy and construction materials has increased, whereas food and water consumption have remained steady. Levels of recycling and sewage treatment are low, and emissions such as particulate matter have decreased. The findings from this study can be used to formulate and apply policies and strategies to improve the sustainability of resources, decrease the reliance on physical resources, increase the efficiency of resource and energy use in urban areas, and enhance sustainable production and consumption in cities. [Copyright &y& Elsevier]