TY - JOUR
T1 - Estimating current and future global urban domestic material consumption
AU - Baynes, Timothy Malcolm
AU - Musango, Josephine Kaviti
PY - 2018/6
Y1 - 2018/6
N2 - Urban material resource requirements are significant at the global level and these are expected to expand with future urban population growth. However, there are no global scale studies on the future material consumption of urban areas. This paper provides estimates of global urban domestic material consumption (DMC) in 2050 using three approaches based on: current gross statistics; a regression model; and a transition theoretic logistic model. All methods use UN urban population projections and assume a simple 'business-as-usual' scenario wherein historical aggregate trends in income and material flow continue into the future. A collation of data for 152 cities provided a year 2000 world average DMC/capita estimate, 12 tons/person/year (+/- 22%), which we combined with UN population projections to produce a first-order estimation of urban DMC at 2050 of similar to 73 billion tons/year (+/- 22%). Urban DMC/capita was found to be significantly correlated (R-2 > 0.9) to urban GDP/capita and area per person through a power law relation used to obtain a second estimate of 106 billion tons (+/- 33%) in 2050. The inelastic exponent of the power law indicates a global tendency for relative decoupling of direct urban material consumption with increasing income. These estimates are global and influenced by the current proportion of developed-world cities in the global population of cities (and in our sample data). A third method employed a logistic model of transitions in urban DMC/capita with regional resolution. This method estimated global urban DMC to rise from approximately 40 billion tons/year in 2010 to similar to 90 billion tons/year in 2050 (modelled range: 66-111 billion tons/year). DMC/capita across different regions was estimated to converge from a range of 5-27 tons/person/year in the year 2000 to around 8-17 tons/person/year in 2050. The urban population does not increase proportionally during this period and thus the global average DMC/capita increases from similar to 12 to similar to 14 tons/person/year, challenging resource decoupling targets.
AB - Urban material resource requirements are significant at the global level and these are expected to expand with future urban population growth. However, there are no global scale studies on the future material consumption of urban areas. This paper provides estimates of global urban domestic material consumption (DMC) in 2050 using three approaches based on: current gross statistics; a regression model; and a transition theoretic logistic model. All methods use UN urban population projections and assume a simple 'business-as-usual' scenario wherein historical aggregate trends in income and material flow continue into the future. A collation of data for 152 cities provided a year 2000 world average DMC/capita estimate, 12 tons/person/year (+/- 22%), which we combined with UN population projections to produce a first-order estimation of urban DMC at 2050 of similar to 73 billion tons/year (+/- 22%). Urban DMC/capita was found to be significantly correlated (R-2 > 0.9) to urban GDP/capita and area per person through a power law relation used to obtain a second estimate of 106 billion tons (+/- 33%) in 2050. The inelastic exponent of the power law indicates a global tendency for relative decoupling of direct urban material consumption with increasing income. These estimates are global and influenced by the current proportion of developed-world cities in the global population of cities (and in our sample data). A third method employed a logistic model of transitions in urban DMC/capita with regional resolution. This method estimated global urban DMC to rise from approximately 40 billion tons/year in 2010 to similar to 90 billion tons/year in 2050 (modelled range: 66-111 billion tons/year). DMC/capita across different regions was estimated to converge from a range of 5-27 tons/person/year in the year 2000 to around 8-17 tons/person/year in 2050. The urban population does not increase proportionally during this period and thus the global average DMC/capita increases from similar to 12 to similar to 14 tons/person/year, challenging resource decoupling targets.
KW - Dmc
KW - Cities
KW - Logistic
KW - Material flow
KW - Regression privilege
KW - World
UR - https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=anu_research_portal_plus2&SrcAuth=WosAPI&KeyUT=WOS:000434490100002&DestLinkType=FullRecord&DestApp=WOS_CPL
U2 - 10.1088/1748-9326/aac391
DO - 10.1088/1748-9326/aac391
M3 - Article
SN - 1748-9326
VL - 13
JO - Environmental Research Letters
JF - Environmental Research Letters
IS - 6
M1 - 065012
ER -