Improve urban waste management and transition to zero-waste cities

Onsite sanitation describes the use of pit latrines, septic tanks, aqua privies, and other systems that accumulate fecal sludge within underground receptacles. These storage areas for human wastes gradually digest the organic materials and emit methane on a continuous basis. They require regular desludging, and ideally the fecal sludge should be transported to treatment facilities (either wastewater treatment plants or dedicated fecal sludge treatment plants).

If the supply chain process is conducted through a transparent system of payment for services, the outcomes can be comparable with piped wastewater systems. However, in many cities in developing countries, informal workers are engaged in the physically demanding and socially degrading work of emptying the sanitary pits, which is often done onto the nearest water body or unused land.

Unless resources are available to build sewer systems in cities in developing countries, onsite sanitation systems will only grow. The trendline in this indicator therefore could go either up or down. There is currently no comprehensive data available on this indicator.

Stakeholders around the world have increasingly recognized the importance of implementing zero-waste strategies. United Nations (UN) Secretary-General António Guterres presided over the first International Day of Zero Waste at a meeting of the UN General Assembly on March 30, 2023. He also announced the formation of the Advisory Board of Eminent Persons on Zero Waste. Also at the global level, the Global Methane Initiative supports a Zero Waste and Organic Cycle initiative in partnership with non-governmental organizations to better capture methane from organic waste.

National policy frameworks that detail zero-waste strategies also play a crucial role in facilitating the creation of municipal action plans with specific zero-waste objectives. Countries are increasingly adopting national policy frameworks for solid waste management and methane capture, and other aspects of transition to zero-waste cities.

At the same time, the potential impact of leadership at the city level is evident through initiatives like the C40 Pathway Towards Zero Waste, “a city-level strategy that supports Global South cities to improve waste management practices and reduce methane emissions.” Signatories as of 2023 include Accra, Amman, Buenos Aires, Curitiba, Dar es Salaam, Dhaka South, Durban, Ekurhuleni, Freetown, Nairobi, Quito, Rio de Janeiro and Tshwane. These cities have committed to reduce their emissions using indicators that are consistent with C40’s Towards Zero Waste Accelerator.

There is currently no comprehensive data available on this indicator.

There are growing opportunities to use digital technologies to monitor methane from waste because electronic sensors have become ubiquitous, now present in infrastructure, vehicles and mobile telephones. Connecting these sensors through the Internet of Things (IoT) vastly enhances the opportunity for big data analytics to assist policymakers in tracking methane capture trends.

For example, the California Air Resources Board oversees and supports emitters implementing a methane reduction program based on the principle of “measuring what needs to be managed.” This involves a tiered observation system that “conducts measurements at many different scales to identify emission sources,” including satellite-based remote sensing mechanisms that can be used to identify high-methane-emitting geographies, which can in turn be validated by ground verification, utilizing existing air quality modeling data and regional inventory analysis.

High-resolution observations of atmospheric methane concentrations are also now available from several platforms, such as the European Space Agency, the World Bank and the Global Methane Initiative. World Bank applied research, for instance, has developed an easily-updated template for tracking atmospheric methane (CH4) concentrations at local and regional scales, with resolution at 2.5 square kilometers. This open access database enables the prioritization of actions to reduce methane emissions from the waste subsectors whose spatial distributions are highly non-uniform across and within countries.

Once this information is ground-truthed by data collection through sensors and by modeling, an accurate sensor-based digital dashboard could provide the basis for creating a digital twin that is an interactive virtual replica of a waste collection and disposal system made possible by connecting electronic sensors. This would provide an automated source of reliable information accessible to all stakeholders.

There is currently no comprehensive global data available on this indicator.

Zero-waste investments represent a public good that extends beyond a city, as pollution often has adverse effects on a geographic region or larger ecosystem. Any successful program therefore requires committed funding in the form of public finance, private finance and cost recovery from service users.

Solid waste management is an expensive, capital-intensive activity and typically absorbs a larger portion of a city’s budget in low-income countries compared to cities in more advanced economies.

Climate funds that prioritize capturing methane and other greenhouse gasses can attract additional funding if investors can be convinced that the institutional and regulatory structures — including contributions from higher levels of government — signal an adequate national commitment to the program. National policies remain key enablers for local actions.

There is currently no comprehensive data available on this indicator.

Zero-waste programs require significant upfront investment to streamline systems for collection, conveyance and disposal, including systems designed for the capture of methane. Some of these aspects require improved institutional processes and regulatory oversight. Others — notably methane capture projects and the regulatory oversight — require private financing that is currently unavailable. Potential investors are often discouraged by the perceived political risks inherent in long-term engagement with city-level stakeholders.

While private financial flows have been absent, official development assistance (ODA) has been largely directed toward cities, with a bias toward cities in upper-middle-income countries. The World Bank, which is the largest international financier of solid waste management infrastructure, directed over $3 billion in financing to middle-income countries between 2010 and 2020 for waste management. Tanzania was the only low-income country that received financing from the World Bank for waste management in that period.

There is currently no comprehensive data available on this indicator.