City-to-city level cooperation for generating urban co-benefits: the case of technological cooperation in the waste sector between Surabaya (Indonesia) and Kitakyushu (Japan)

• Surabaya and Kitakyushu have cooperated by implementing THC method at household.
• Surabaya has reduced organic waste through the THC method.
• Large amounts of GHG emission were avoided due to the adaptation of the method.

In recent years, Surabaya has confronted municipal solid waste (MSW) with a partnership with Kitakyushu city for the use of the Takakura Home Composting (THC) method. A large number of Takakura bins have been distributed to households and cadres have been involved in educating local households about organic waste reduction through the method. In the past decade (2005–2013), the city has reduced organic waste through many diverse composting methods such as THC and about 3421 Mt of CO2 equivalent emissions could be reduced annually. By adapting the THC method, Surabaya has made positive changes to its MSW management practices. This kind of city-to-city technological cooperation has facilitated larger processes in other cities in Indonesia and elsewhere. This article discusses the lessons learned pertaining to the adaptation of the THC method in Surabaya to understand how city-to-city cooperation can work to boost climate co-benefits in urban areas, particularly in the waste sector.