Greenhouse gas implications of peri-urban land use change in a developed city under four future climate scenarios

Present decisions about urbanization of peri-urban (PU) areas may contribute to the capacity of cities to mitigate future climate change. Comprehensive mitigative responses to PU development should require integration of urban form and food production to realise potential trade-offs. Despite this, few studies examine greenhouse gas (GHG) implications of future urban development combined with impacts on PU food production. In this paper, four future scenarios, at 2050 and 2100 time horizons, were developed to evaluate the potential GHG emissions implications of feeding and housing a growing urban population in Sydney, Australia. The scenarios were thematically downscaled from the four relative concentration pathways. Central to the scenarios were differences in population, technology, energy, housing form, transportation, temperature, food production and land use change (LUC). A life cycle assessment approach was used within the scenarios to evaluate differences in GHG impacts. Differences in GHG emissions between scenarios at the 2100 time horizon, per area of PU land transformed, approximated 0.7 Mt CO2-e per year. Per additional resident this equated to 0.7 to 6.1 t CO2-e per year. Indirect LUC has the potential to be significant. Interventions such as carbon capture and storage technology, renewables and urban form markedly reduced emissions. However, incorporating cross-sectoral energy saving measures within urban planning at the regional scale requires a paradigmatic shift.