The city of Oslo has set an overall target to reduce its CO2 emissions by 50% by 2030 and to become carbon neutral by 2050xxiii compared to 1990. One of the measures needed to achieve this ambitious target is an integrated waste management system, which Oslo launched in 2006 with its Waste Management Strategy (WMS), aiming to establish a “recycle and reuse” society. The WMS builds on national strategies and promotes the waste management hierarchy (see Section 2.2). Incineration and landfill are seen as the least desirable forms of waste management and represent the last resort within Oslo’s strategy. As such, a large part of the WMS concentrates on the behavioural habits of citizens to make them carry out waste reduction, reuse and recycling. In 2012, Oslo implemented the circular waste management system which includes recycling, producing biogas and bio fertilizer from bio waste, and energy recovery for district heating and electricity production.
In the current Oslo’s waste management system household waste is sorted by citizens themselves into various fractions. Since 1997, paper and drink cartons have been collected by the city after separation in households, whereas glass and metal packaging are delivered by households to about 700 local collection sites around the city (in general within a radius of 300 meters). Sorting of food waste and plastic packaging at source started in October 2009, and since June 2012 all households in Oslo are included. Plastic packaging is deposited in blue bags while food waste goes in green bags. A total of 85.5 kg of food waste per person was generated in 2014, 40% of this which was separated into green bags. By making food waste visible, the system also appears to have made residents more aware of the volume of food that is wasted, as the total volume of food waste has reduced by 5% since collections started. Residual waste is discarded in other plastic bags and all bags are discarded into the same waste containers before coloured bags are separated from each other in optical sorting plants.xxiv
This system required no logistical changes to the existing waste management system and could be implemented rapidly – contrary to the alternative of adding more waste containers and routes for the collection vehicles.xxv The plastic packaging is recycled and the food waste is supplied to a biological treatment plant with capacity of 50,000 tons/year, which produces enough biogas and bio fertilizer to run about 150 buses and provide about 100 medium-sized farms with bio fertilizer yearly.
Two waste-to-energy plants incinerate residual waste from the city, with a capacity of 410,000 tonnes of waste per year and the energy used for district heating and electricity generation. The total annual energy production is about 840 GWh heat and 160 GWh electricity. The heat energy meets the need of about 84,000 households through the district heating system, while the produced electricity is delivered to Oslo’s schools, together with electricity produced from landfill gas from the city landfill closed in 2007.
In 2011, about 240,000 tonnes of household waste was collected and of this 1% was reused, 33% recycled (37% in 2014), 60% energy-recovered and only 6% went to landfill. The city aims to recycle 50% of the household waste by 2018. Currently, Oslo is drafting a new waste strategy for the 2015-2025 period with enhanced goals and a closer linking to the circular economy.
Reasons for success
Oslo has successfully built an integrated waste management system based on adaptation of a legacy waste collection system which was quickly upgraded through the use of innovative technologies. It also benefitted from early recognition of the importance of behaviour change in reducing waste generation and perfecting source separation of waste. The waste management strategy was also driven by the city’s long-term GHG emissions reduction and waste reduction goals. Oslo and Cambi AS received the Norwegian Research Council’s innovation reward in 2012 for their approach of system thinking around waste and their biogas/bio fertilizer production plant.
When/why a city might apply an approach like this
Cities in need of implementing fast transitions in their waste systems can learn from these successful innovative technology solutions in waste separation and disposal reduction, as well as communication strategies, and citizen engagement. Cities planning long-term strategies can also follow the above examples to develop more ambitious plans.
C40 Good Practice Guides
C40's Good Practice Guides offer mayors and urban policymakers roadmaps for tackling climate change, reducing climate risk and encouraging sustainable urban development. With 100 case studies taken from cities of every size, geography and stage of development around the world, the Good Practice Guides provide tangible examples of climate solutions that other cities can learn from.
All references can be found in the full guide.