More than 50% of the world’s population lives in cities. Its buildings consume more than a third of the energy and generate 40% of the emissions. This makes cities in general and their buildings in particular priority points of attention for policymakers and utilities. This paper uses population density as a variable to know its influence on energy consumption and emissions produced in buildings. Furthermore, to show its effect more clearly, the influence of the climate was eliminated. The usual energy consumption in buildings is thermal and electrical. The study was carried out at the city level, both per inhabitant and per household. The area actually occupied by the city was considered. The proposed method was applied to the case of Spanish cities with more than 50,000 inhabitants. The results show that the higher the population density, the higher the energy consumption per inhabitant and household in buildings. The consumption of thermal energy is elastic, while that of electrical energy is inelastic, varying more than 100% between extreme groups. Regarding CO₂ emissions, the higher the population density, the higher the emissions. Emissions of electrical origin barely vary by 2% and are greater than those of thermal origin. In addition, the proportion of emissions of electrical origin, with respect to the total, decreases with increasing population density from 74% to 55%. This research aims to help policymakers and utilities to take the appropriate measures that favor the use of renewable energies and reduce CO₂ emissions.

中文翻译：

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人口密度对二氧化碳排放的影响消除气候影响

世界上超过 50% 的人口居住在城市。它的建筑物消耗了三分之一以上的能源，并产生了 40% 的排放量。这使得整个城市及其建筑物成为政策制定者和公用事业单位的特别关注点。本文以人口密度为变量，了解其对建筑能耗和排放的影响。此外，为了更清楚地显示其效果，消除了气候的影响。建筑物中通常的能源消耗是热能和电力。这项研究是在城市层面进行的，包括每个居民和每个家庭。考虑了城市实际占用的面积。所提出的方法被应用于拥有超过 50,000 名居民的西班牙城市的案例。结果表明，人口密度越高，建筑物中每个居民和家庭的能源消耗量越高。热能的消耗是弹性的，而电能的消耗是无弹性的，在极端组之间变化超过 100%。关于 CO₂排放量，人口密度越高，排放量越高。电源的排放几乎没有变化 2%，并且大于热源的排放。此外，电力排放占总量的比例随着人口密度从 74% 增加到 55% 而下降。本研究旨在帮助政策制定者和公用事业单位采取适当措施，促进使用可再生能源并减少 CO ₂排放。