Posted 5 June 2018 - 2:15pm
Carbon footprint analysis expert and CRCLCL project leader UNSW Associate Professor Tommy Wiedmann has contributed to an international report revealing cities have a 60% larger carbon footprint than previously estimated.
The report was carried out by the C40 Cities Climate Leadership Group (C40) in partnership with UNSW, University of Leeds and Arup and includes the impact of goods and services trade between cities and the rest of the world. Professor Wiedmann analysed the emissions associated with the goods and services consumed by the residents of 79 cities including Sydney and Melbourne.
The resulting report, Consumption-based GHG Emissions of C40 Cities, focuses on the consumption of goods and services by city residents including food, clothing and electronic equipment, as well as the carbon emitted by raw materials, manufacture, distribution, retail and disposal.
“Most studies focus on carbon emissions within city boundaries, but people rely heavily on the supply of goods and services from outside a city’s physical boundaries, and the emissions associated with these supply chains are significant,” said Professor Wiedmann. “We found that about half of Sydney and Melbourne’s carbon footprint came from outside the city boundary,” he said.
The findings revealed a detailed picture of the supply chains that local councils, businesses and citizens can potentially influence with their climate action and the data provides both a benchmark and an opportunity for all cities to reduce global emissions if consumption is addressed.
“The efforts being made to reduce emissions from buildings and traffic are good, but they are not the only emissions we need to look at. We need to make equal efforts to reduce emissions in building materials, from food production and what we consume,” added Professor Wiedmann.
The report also highlighted the fact that since the 1997 Kyoto protocol global carbon emissions have also increased by 60% and using renewable energy and mass transit will not be enough to meet the targets set in the 2015 Paris Agreement.
As Professor Wiedmann says, “Smart and sustainable cities of the future will have to be zero carbon ‘inside’ and low carbon ‘outside’. They will have to be regenerative, absorbing CO2 emissions from the atmosphere through green infrastructure, and making the most of reusing, repurposing and recycling goods, materials and waste.”
To date, the mayors of 35 C40 cities, including Sydney and Melbourne, have publicly committed to implementing ambitious climate action plans by 2020 that go beyond national commitments to achieve the highest goals of the Paris Agreement at the local level.