This is how cities can reduce emissions with waste-reduction solutions

With the world’s population rapidly approaching 8 billion, the waste we produce is a growing problem.

Each person on the planet generates an average of 0.74 kilograms of waste a day. However, this estimate by the World Bank includes data ranging from 0.11kilograms to 4.54 kilograms, with high-income countries producing more than a third of the 2.01 billion tonnes of global waste generated annually.

The things we throw away create many by-products, and methane is one of the worst offenders. More potent than CO2, it’s responsible for as much as 16% of global greenhouse gas emissions (GHGs).

Methane is responsible for around 30% of the rise in global temperatures since the industrial revolution, according to the International Energy Agency (IEA). Waste was the fourth leading source of methane emissions in 2021, producing 73 megatonnes, it says.

The waste sector is responsible for 20% of global methane emissions and 3.3% of global greenhouse gas emissions, according to a new report, 'Zero Waste to Zero Emissions: How Reducing Waste is a Climate Gamechanger ' from the Global Alliance for Incinerator Alternatives (GAIA). The report explains that waste management methods can help the world fight global warming in three ways: climate mitigation, adaptation, and additional societal benefits.

Reforming the sector could cut global methane emissions by 13%.

Waste reduction solutions like segregation, composting, and recycling could reduce the sector’s total emissions by 84%, according to the report. This is equivalent to taking all US motor vehicles off the road for a year.

Such approaches could be extended to other sectors: “At least 70% of global emissions come from the manufacture, transport, use and disposal of goods, and a focus on waste reduction could significantly reduce the emissions in these sectors too,” says GAIA.

Zero-waste solutions can also help cities become more resilient to the existing impacts of climate change by mitigating floods, reducing disease transmission and improving soil quality.

More than 550 municipalities around the world are currently implementing zero-waste policies, according to the report.

Business-as-usual and zero-waste scenarios were modelled to ascertain the potential waste emissions reductions of eight cities in a range of sizes and with different resources and climatic conditions, as detailed in the chart below.

On average, the eight cities modelled generated an 84% reduction in GHG emissions.

South Korea’s capital, Seoul could potentially see the biggest GHG reduction in a zero-waste scenario, the report’s case studies reveal. Its current waste system, however, is already net-negative due to a robust separate collection and recycling system. The city also has little food waste going into landfills.

The majority of Seoul’s GHG emissions come from incinerators, the report’s researchers say. If these are phased out, together with its other waste solutions efforts, the city could save more than 885% of annual GHG emissions or more than 538 tonnes of CO2.

The case studies revealed several commonalities between the countries, most significant of which was the benefits that could come from correct management of organic waste: “In all the cities we analyzed, except Seoul, separate collection and treatment of organics has the greatest potential to reduce GHG emissions.”

Landfill use is found to be the biggest source of emissions in several cities, the findings show. By moving away from this method, Detroit could lower waste-sector emissions by 102%, Temuco by 73%, Dar es Salaam by 65%, and Bandung by half.

More than 25% of countries’ current climate plans neglect the waste sector, and now is the time for global leaders to take bold and urgent action, GAIA says. At the COP27 climate conference, currently underway in Sharm el-Sheikh, Egypt, such issues will be addressed. The host nation is putting forward the ‘Africa Waste 50’ initiative, which plans to recycle and treat 50% of all waste produced in Africa by 2050.

“Previous climate talks have largely overlooked the potential of reforms to the waste sector, particularly for reducing methane, which over 100 countries have now pledged to do. Zero waste strategies are the easiest way to rapidly and cheaply bring down emissions while building climate resilience, creating jobs, and promoting thriving local economies,” stated Mariel Vilella, co-author of the report and director of GAIA’s Global Climate Program.