Improved Waste Management is Key to Delivering the Methane Cuts Needed to Prevent Catastrophic Warming

Achieving the dramatic methane cuts necessary to meet the Paris Agreement target of keeping warming well below 2 degrees Celsius (and preferably to 1.5) will require tackling every emitting sector, including waste which accounts for 20 per cent of human-made methane emissions.

Methane is responsible for about half of the one degrees Celsius rise in global temperature since the preindustrial era, according to the latest report of the Intergovernmental Panel on Climate Change (IPCC). The Climate and Clean Air Coalition’s (CCAC) Global Methane Assessment shows that rapid methane reductions could avoid almost 0.3 degrees of warming by 2045.

“Reducing methane emissions is something that leads to tremendous public health benefits, agricultural benefits, labour productivity benefits, and contributes to climate change mitigation more broadly. It is something we must do because the climate damages that are accumulating so quickly— and unfortunately making headlines around the world— are only going to get worse over the next couple decades,” said Drew Shindell, CCAC Special Advisor for Action on Methane. “We also need to keep HFCs under control and we need to target black carbon but the strongest lever we have in the near term is methane.” 

The fossil fuel sector has received significant attention for its methane reduction potential, and for good reason: it’s responsible for 35 per cent of human-caused emissions and the majority of mitigation measures can be done at negative or low cost. To achieve the scale of methane cuts needed, however, reductions must occur in all sectors, including agriculture (responsible for 40 per cent) and waste. 

As much as 60 per cent of available measures to reduce emissions in the waste sector are either negative cost or low cost. The targeted measures identified in the Global Methane Assessment include reducing waste, composting, better solid waste management strategies like separating and reusing recyclables, and energy recovery of landfill gas. 

One major opportunity is reducing food loss and waste, which alone can reduce methane emissions by 15 per cent by 2030. About a third of the food produced for human consumption is thrown away — that’s 1.3 billion tons, much of which ends up in landfills. Food waste costs the global economy nearly $1 trillion each year and is responsible for squandering almost a quarter of all the water used in agriculture.

It isn’t just an emissions reduction opportunity, it’s also a major development strategy: 690 million people went hungry in 2019 and another 3 billion people couldn’t afford a healthy diet. Halving global food waste at the retail and consumer level and reducing food loss along production and supply chains by 2030 is one of the Sustainable Development Goals. Moreover, methane is a key ingredient in the formation of ground-level ozone, a powerful climate forcer and dangerous air pollutant.

“The overall growth in global landfill emissions has been driven by a number of factors, including population growth, economic development, and urbanization in developing countries,” said Alice Alpert, U.S. State Department,. “From a practical perspective, that means that the public health and economic benefits of methane emissions reduction strategies in the waste sector will be experienced locally, from reducing air pollutants from open burning of waste to generating clean, locally available biogas from anaerobic digestion of organic waste diverted from landfills.”

Food waste and loss can be reduced with low-cost strategies such as improving food cold chains, consumer education, and donating excess food. Despite this potential, only 11 countries included food loss in their Nationally Determined Contributions (NDCs) and none include food waste, said Clementine O’Connor, Programme Management Officer, Sustainable Food Systems at UNEP. 

One CCAC partner country making significant progress in the waste sector is Chile. The Canada-Chile Reciclo Organicos Programme will help the country achieve their updated Nationally Determined Contributions (NDCs) by strengthening their Monitoring, Reporting and Verification (MRV) systems and spreading the adoption of low-emissions waste practices through community engagement. A major achievement is Chile’s National Organic Waste Strategy, which aims to  increase municipal organic waste recovery from 1 per cent to 66 per cent by 2040 through composting and reducing food waste. It also aims to have half a million families, 5,000 schools, and 500 neighbourhoods composting.

A pilot project in the Maule region of Chile is converting organic waste into fly meal that can be used for dog or salmon food.

There’s still work to do refining these strategies, says Marcelo Mena Carrasco, former Minister of Environment and current Director of the Climate Action Centre at the University of Valparaiso and, including restructuring funding for waste collection and composting so that it’s better distributed across income levels. Currently, two-thirds of homes aren’t paying for waste collection which means that currently these changes can only occur at scale in higher-income neighbourhoods. 

Another leader on this front is Medan City. With a population of 2.85 million it is Indonesia’s third largest city and produces almost 2,000 tons of waste per day. That number is increasing as Medan’s population and consumption per capita also grow.T he city’s landfill will be full in the next two to three years.

Medan City set a waste reduction target of 30 per cent, in line with Indonesia’s national target. The CCAC’s Waste Hub is helping the city achieve this, first by carrying out a rapid assessment from 2017-2018 to better understand the local challenges and opportunities of waste management and then developing a work plan based on the findings. The work plan mapped relevant regulations and policies, administrative structure, and made a plan to implement the three Rs (reduce, reuse, recycle). It found that if Medan City could achieve 100 per cent waste collection and 10 per cent reduction, the city could reduce greenhouse gas emissions by 29 per cent. The more ambitious 30 per cent waste reduction target would reduce emissions by 41 per cent. Better waste management would also provide Medan City with co-benefits like improved sanitation and living conditions, and reduced costs from waste.

The Medan Zero Waste City Initiative is working to achieve these goals through a community waste management system developed with Medan’s environment agency, women’s associations, and community groups that drives community engagement for composting, stopping waste burning, and increasing the three Rs. 

Medan is also pioneering a new method to manage organic waste called eco enzyme, a liquid made from fermenting organic waste that women’s groups are producing and using as a cleaner and plant fertilizer. 

“We don't need technologies that are difficult to implement, we just need simple technologies that are easily adopted and practiced by communities. Starting something on a small scale that’s capable of being replicated can have a huge impact on organic waste,” said Willy Irwan, Head of the Division for Infrastructure and Spatial Planning, Local Planning and Development Board (BAPPEDA), City of Medan, Indonesia. “To empower a community, work with the organizations that already exist because they know their needs and how to take responsibility for changing their city.”

To help more countries achieve this work, the U.S. Environmental Protection Agency, on behalf of CCAC, developed the Solid Waste Emissions Estimation Tool (SWEET) to help better measure waste emissions and reductions and the OrganEcs tool, which helps estimate the costs of an organic waste management project.

With the CCAC’s leadership, bold commitments to reduce methane across sectors are catching on around the world. Most recently, the United States and the European Union launched the Global Methane Pledge at COP 26 in Glasgow, rallying countries around a commitment to reduce global methane emissions by at least 30 per cent by 2030. Helping reduce methane from waste will ensure the world can meet that target this decade.