Energy Consumption in Cities

Energy consumption is the largest contributor to carbon dioxide (CO₂) emissions, the leading cause of climate change. It is important to understand which sectors consume the most energy to take appropriate remedial actions for emissions reduction. It is helpful to view cities as organic systems that have their own metabolism. ¹ The metabolism of a city involves physical inputs – energy, water and materials – that are consumed and transformed, by means of technological and biological systems, into wastes and goods, or the city’s outputs. Like any thermodynamic system, urban energy consumption can either be efficient or inefficient. An environmentally successful and energy efficient – or sustainable – city should ideally combine economic growth with social equity and minimum waste production (including greenhouse gas emissions).