If a city has overall emissions reductions goals, SWEET helps them better understand how investments in waste management in particular will contribute to those goals, which helps cities prioritize interventions and make financing decisions. The tool can also help the city see and how their emissions compare to other cities.
“One of the things the tool does best is help communicate to people how significant emissions from landfills are relative to other emissions sources in the waste sector,” said Joe Donahue, Senior Associate, Abt Associates. “Landfill emissions just dwarf everything else and I think until this tool existed, a lot of cities didn’t understand that.”
Unregulated dumpsites, in particular, are a huge problem for methane and black carbon emissions. According to the International Solid Waste Association, dumpsites receive 40 percent of the world’s waste and the globe’s 50 biggest dumpsites affect the daily lives of 64 million people. In low-income countries, just 36 percent of the population has a trash collection service.
A major objective for the tool was that it would help cities connect the dots between the waste sector, climate, clean air, and other development indicators. Waste can seem like an intractable problem and SWEET can help cities recognize that intervening in the waste sector is a lot easier than it seems— and that the multiple benefits can be big.
“Once we help them connect the dots between food security, logistics, transport, job generation, environmental impact, they realize that with relatively simple actions and decisions they can mitigate emissions,” said Gabriela Otero, a Technical Coordinator at ABRELPE who has helped multiple cities in Brazil start using SWEET.
Ms. Otero and her team started running the SWEET tool in 2017 in the southern city of Curitiba and then soon after in Sao Paulo, the most populous city in Brazil with over 12 million people.
“When you see how big the numbers are for potential emissions avoided if they make the right decisions it is really attractive,” said Otero. “The SWEET tool is a very good technical and political commitment tool.”
Already, the mayor of Sao Paulo has incorporated the emissions mitigations calculated using SWEET’s tool into the city’s strategic goals, citing CCAC’s Waste Initiative as the reference point for their goal of reducing and diverting solid waste from landfills. The tool showed that diverting organic waste from landfills, including by composting it, can lead to emissions mitigation which helped motivate an increase in the number of decentralized composting facilities.