City-Level Decoupling-Full Report

City-Level Decoupling: Urban resource flows and the governance of infrastructure transitions

locally deposited wastes (landfills), exported wastes (from CO 2 to sewage), or some form of recyclable waste (the large bulk of these wastes being a cause of environmental degradation). • The most significant outputs are Domestic Material Output (DMO) which includes the domestic wastes deposited into nature locally (Domestic Processed Output - DPO), plus the exported wastes that are eventually deposited into non-local natural systems, in addition to exported materials (minus wastes). This approach makes it possible to distinguish between the direct and indirect flows that obtain resources from within and beyond the city, then flow through the city with some ending up as NAS, and other flows moving into or beyond the city as wastes, goods and services. Urban infrastructures conduct these flows. For example, the domestic material input per capita (DMI/cap) for a city

to Stock (NAS). In mature cities (located largely in developed countries) inhabited by a large established middle class, a relatively small proportion of materials entering the city system annually will end up as NAS while the bulk of materials will be consumables (pumped through the city by ever-rising energy use). The opposite applies to fast growing cities in developing countries where foreign and local investments are going into the rapid construction of new stock (buildings and infrastructures). That said, ageing districts or redundant infrastructures can become the focus of regeneration initiatives that give new values to some lands, while economic shocks can overnight make entirely new districts redundant as businesses close down or property values collapse. • Materials that do not result in NAS will be processed as material throughputs (MT) that enable the city’s economy to operate (e.g. fuels, food, water), ending up as either

Table 4.1 Explanation of indicators and abbreviations used in Figure 4.1 60

Indicator/ abbreviation

Explanation

BI

balancing inputs balancing outputs

BO

DMC

domestic material consumption = DMI - exports corrected domestic material consumption = DMI - imported wastes - exports except wastes direct material input DMI + BI = NAS + DMO + BO

DMC corr

DMI

DMO DPO LEPO

direct material output

domestic processed output

local and exported processed output = DPO + exported flows to nature

NAS TDO TMI TMO TMR

net addition to stock total domestic output

total material input TMI + BI = NAS + TMO + BO

total material output

total material requirement

Source: Barles 2009:901

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