Reforming how world deals with waste is critical to keeping warming below 1.5°C, report finds

  • Waste sector accounts for 20% of global methane emissions, a stronger greenhouse gas than CO2
  • Better waste management could cut waste sector emissions by 84% (1.4bn tonnes) and significantly reduce emissions in other sectors 
  • São Paulo, Detroit, and others could reach net-negative sector emissions by 2030
  • Governments preparing for COP27 should prioritise action on waste 

The introduction of ‘zero waste’ systems in cities around the world would be one of the quickest and most affordable ways to reduce global heating and stay below 1.5°C of warming, according to a new report released by Global Alliance for Incinerator Alternatives (GAIA). 

The waste sector accounts for 3.3% of global greenhouse gas emissions, and a fifth of global methane emissions. Introducing better waste management policies such as waste separation, recycling, and composting could cut total emissions from the waste sector by more than 1.4 billion tonnes, equivalent to the annual emissions of 300 million cars – or taking all motor vehicles in the U.S. off the road for a year.   

But this figure underestimates the potential impact of waste management reforms. 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. For example, manufacturing something from recycled aluminium uses 96% less energy than starting with raw materials. 

The potential for zero waste policies to reduce methane emissions is also critical. Methane is over 80 times as potent as CO2 but lasts only a short time in the atmosphere. Reforming the waste sector could cut global methane emissions by 13% globally. This would bring enormous climate benefits within the next few decades and ‘buy time’ to cut other emissions. 

Report co-author Dr. Neil Tangri at GAIA, said: “Better waste management is a climate change solution staring us in the face. It doesn’t require flashy or expensive new technology – it’s just about paying more attention to what we produce and consume, and how we deal with it when it is no longer needed.”

“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 co-author Mariel Vilella, Director of GAIA’s Global Climate Program. 

“As we prepare for another round of UN climate negotiations, we have a unique opportunity to put waste firmly on the agenda. Without concrete commitment from global leaders to zero waste, we will not be able to meet the 1.5° C climate target.” 

GAIA’s report modelled potential emissions reductions from eight cities around the world. They found that on average, these cities could cut waste sector emissions by almost 84% by introducing zero waste policies, with some, such as São Paulo  and Detroit, able to reach net-negative emissions by 2030. 

“GAIA’s report scientifically demonstrates that zero waste can actually get São Paulo to net-negative emissions from the waste sector, while promoting new jobs, providing a decent dignified livelihood to waste pickers and compost to support local agro-ecological farmers, groups who have been historically marginalised,” stated Victor  H. Argentino de M. Vieira of Brazil-based organisation Instituto Pólis. “What are our leaders waiting for?  The time is now to prevent waste and reduce poverty in São Paulo.”

The report also maps out how zero waste systems could help cities adapt to the escalating climate crisis, preventing both flooding and droughts, strengthening soil and agriculture, reducing disease transmission and generating employment opportunities. 

Despite this, more than a quarter of countries’ current climate plans neglect the waste sector. Waste management will be one of the critical topics tackled at the 2022 United Nations Climate Change Conference (COP 27) in November, where host nation Egypt plans to put forward the Africa Waste 50 Initiative, aimed at treating and recycling 50% of waste produced in Africa by 2050. 

In order to keep global warming below 1.5°C, as set out in the Paris Agreement, and prevent catastrophic climate change, GAIA is urging global leaders to take urgent and bold action on zero waste by:

  • Incorporating  zero waste goals and policies into climate mitigation and adaptation plans.
  • Prioritising food waste prevention and single-use plastic ban.
  • Instituting separate collection and treatment of organic waste.
  • Investing in waste management systems, recycling, and composting capacity.
  • Establishing institutional frameworks and financial incentives for zero waste including regulations, educational and outreach programs, and subsidies to recycling and composting. 

Janez Potočnik, Co-Chair of the International Resource Panel of the UN Environment Programme, former European Commissioner for the Environment states: “This report demonstrates the huge importance of aligning our waste systems with climate goals. It shows how cities are already working to eliminate greenhouse gas emissions from waste while building climate resilience and creating livelihoods. It highlights the absolute necessity of reducing root sources of waste through changing our production and consumption patterns – using all the tools at our disposal to achieve the deep emissions reductions we need.” 

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Note to Editor:

The full report can be found at:


To ascertain the global emissions reduction potential of zero waste strategies, GAIA worked with local researchers to collect city-specific waste composition and generation data from eight diverse cities around the world. Bandung (Indonesia), Dar Es Salaam (Tanzania), Detroit (USA), eThekwini (South Africa), Lviv (Ukraine), São Paulo (Brazil), Seoul (South Korea), and Temuco (Chile) were chosen to represent a wide range of conditions and circumstances, including climates, waste generation patterns, affluence and poverty, and current waste management systems. Projected diversion efforts focused on organics and easy-to-recycle materials such as paper, cardboard, metal, and glass. The degree of ambition or effort required for the potential zero waste scenario, as measured by the diversion rate (~50%), is well below what has already been achieved by multiple large cities in similar or shorter timeframes (~80%).  

GAIA found that the eight cities they studied could achieve average emissions reductions of 84%. Scaled up to a global level (i.e. assuming comparable actions taken in other cities and countries around the world), this represents a potential reduction of 1.4 billion tonnes of greenhouse gas globally (3% of the global total), and reduction of 42 million tonnes  in methane emissions (13% of the global total).