City-Level Decoupling-Full Report

the urban development process in ways that do not result in TMC levels of 15 to 40 t per capita. The MIT study only deals with flows through the urban system and not with net addition to stocks (NAS). A similar comparative study for NAS does not exist, but a projection of how an NAS analysis could relate to energy consumption is presented in Figure 4.3. The figure projects that demand for materials to add to stocks would spike after a period of rapid urbanisation (assuming the necessary economic preconditions are in place to support these investments). At the core of this is a massive increase in demand for construction materials, the bulk of which are Net Addition to Stocks (NAS) (buildings, infrastructure). As urbanisation stabilizes over time and average income levels steadily rise, the demand for construction materials tapers off and the demand for energy rises (with, of course, an associated rise in emissions). The rising energy curve as urbanisation stabilises and incomes rise is directly related to the type of infrastructures that are designed and implemented in cities. This helps illustrate the core conclusion of this report: infrastructures can be designed in such a way that the materials consumption curve peaks at a lower level of consumption, and that the subsequent energy requirements will be reduced accordingly because the infrastructures and buildings have been appropriately designed to achieve the same level of well-being with less resource consumption and lower CO2 emissions (resource and impact decoupling, respectively). While helpful to illustrate a particular ideal type that has really only been manifested to the full extent in developed countries, Figure 4.3 ignores what has been referred to as heterogenous urbanisation and the peri- urbanisation of the urban poor in cities in the developing world. In these cities the materials curve may not rise and fall in this way, but may instead reveal a constant gradual increase as net additions to stocks constantly lag behind economic growth due to the absence of resources for major infrastructure works and building construction. However, the energy

• Type 12 cities are are energy intensive economies with high carbon emissions. Although total energy consumption is high, electricity consumption is relatively low because significant populations of these cities are earning low personal income. • Type 13 cities are in countries which are technologically advanced producers of coal, cement, food and beverages, and textiles. Construction plays a major role in these economies. As a result, TMC and CO 2 emissions are very high, and biomass and construction minerals are medium/ high. Relatively low electricity and industrial minerals/ores reflects the modest large heavy industrial base. • Type 14 cities are located in the world’s oil producing countries. TMC, water and construction minerals consumption is very high due to the affluence in these cities, with low levels of consumption of biomass industrial minerals and ores due the absence of industries that require these inputs and the arid regional conditions. Unsurprisingly, energy and CO 2 levels are high. • Type 15 cities are located in the advanced low density industrial nations. The energy and material intensity of these economies plus high levels of personal affluence explain the high resource consumption levels in their cities. Their low density compared to European cities also plays a role here. that the cities clustered under Types 1-6 plus 8 will go through a conventional process of modernisation (industrialisation, urbanisation) that will result in their TMC rising from between 2 and 4 t per capita to the same level as the most unsustainable cities in the world (Types 10 to 15) where TMC is between 15 and 40 t per capita. The challenge is for cities in the developed world to reduce their TMC per capita, and for cities in the developing world to find ways of managing This analysis reinforces the overall argument of the report. Business as usual will mean

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