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What initiatives, policies and technologies can significantly reduce greenhouse gas emissions from waste and waste management?
Submit proposals:
Rules: All entrants must agree to the 2015 Contest Rules. and Terms of Use.
Deadline: Saturday, June 13, 11:59 PM Eastern Time
Judging Criteria & Prizes: See below.



According to the Intergovernmental Panel on Climate Change (IPCC), post-consumer waste disposal will account for more than 1.6 gigatons (Gt) carbon dioxide equivalent (Gt CO2-eq) in greenhouse gas (GHG) emissions in 2030, 3 percent of the global total. This primarily includes emissions from the disposal of liquid waste through sewage treatment and solid waste through landfills and incineration.

In the First Assessment Report from the Urban Climate Change Research Network (UCCRN), cities (meaning urban areas) are identified as being “at the forefront of the challenge of climate change…uniquely positioned to take a leadership role in both mitigating and adapting to it.” With the majority of population growth projected to take place in cities, improvement initiatives in waste management can make a significant impact. 

This contest seeks proposals that address any aspect of waste management: reducing emissions through better waste water/landfill/incineration practices; using GHGs generated from trash to generate energy via waste to energy systems; innovative recycling schemes that reduce the amount of waste; or other initiatives that either reduce consumption patterns or increase the use of recycled content in new products. Also welcome are new approaches to international policy and accounting.

Key Issues

The IPCC outlines a range of possible strategies for reducing emissions from waste management:

·       landfilling with landfill gas recovery (reduces CH4 emissions),

·       post-consumer recycling (avoids waste generation and reduces emissions from the  production process),

·       composting of selected waste fractions (avoids GHG generation),

·       processes that reduce GHG generation compared to landfilling (thermal processes including incineration and industrial co-combustion, Mechanical Biological Treatment or MBT with landfilling of residuals, and anaerobic digestion)

Differing international waste management practices

Waste management can be a challenging topic in international climate negotiations because practices in separation, recycling and composting, and final waste management differ considerably from country to country.

Waste separation.  Waste composition varies by income level. Both formal and informal sectors are involved in separating waste streams; the percentage of each varies by region and level of service provided by government.  Higher levels of waste separation allow greater recycling, composting, and reuse of products to take place.

Recycling. The rate of waste recycling depends on the availability of (sorted) materials through formal and informal sectors, the presence or absence of market drivers, and the ability achieve process requirements that transform waste products into usable materials.  Recycling consumes energy and fossil fuels, and as a result, emits CO2.  For certain materials, the recycling process can be more efficient than the extraction of raw materials. 

Composting.  The success of composting materials relies on the adequate separation of organic wastes, the presence or absence of market drivers, and the awareness of its benefits.  The use of anaerobic digestion is rising in popularity, though preventing contamination at a large scale can be a challenge.  CO2 is released from the composting process, though the resulting reduction of emissions associated with transporting less waste for incineration and/or landfilling is greater in scale.

In terms of the final step of waste management, the US primarily uses closely monitored landfills, and Europe and Japan predominately use incineration. Developing countries often rely on open landfills.

Incineration.  The GHG footprint of incineration depends on whether the process is simple incineration, which only emits CO2, or part of a waste to energy system. The latter also emits CO2, but the energy produced reduces the overall demand for energy, most of which is produced by burning fossil fuels, which also emit CO2.

Landfills generate methane, a very powerful GHG, with twelve times more warming effect than CO2 over its lifetime. As many developing countries are lagging behind in waste management techniques, most cities rely on dumping in open landfills and releasing untreated sewage into waterways.

While the average per capita waste generation remains below that of developed countries, rapid rural to urban migration and changing consumption patterns are causing rapid growth in waste production in developing countries. In addition to methane emissions, developing countries are faced with serious public health impacts resulting from the lack of sustainable waste management.

Flaws in the GHG accounting system

Another important issue is accounting for emissions generated in waste management. There are flaws in the current accounting system, indeed, there is not even complete agreement on what should be accounted for: simply emissions generated in the course of waste disposal? or should emissions from the production process avoided through practices like recycling also be included?

Ideas of mandates for product and packaging manufacturers to use minimum amounts of recycled content in their products, which would encourage a more sophisticated system of recycling and create strong secondary markets for the recyclable materials collected.  This could also include more widespread use of “Extended Producer Responsibility” policies that are gaining acceptance in certain parts of the world.

Judging Criteria

Judges will be asked to evaluate proposals on the following criteria: feasibility, novelty, impact and presentation quality.  Winning proposals will be especially strong in at least one of the first three dimensions, and also well presented.  For details about the judging criteria, click here.


Judges Choice and Popular Choice winners will receive a special invitation to attend selected sessions at MIT’s SOLVE conference and present their proposals before key constituents in a workshop the next day, where a $10,000 Grand Prize will be awarded. A few select Climate CoLab winners will join distinguished SOLVE attendees in a highly collaborative problem-solving session.

Resources for Proposal Authors

•   IPCC, Climate Change 2007: Working Group III: Mitigation of Climate Change, Chapter 10: Waste management

•   Frank Ackerman, William Moomaw, and Robin Taylor, Greenhouse Emissions from Waste Management. A survey of data reported to UNFCCC by Annex I countries, 2003.

•   World Bank, What a Waste: A Global Review of Solid Waste Management, Chapter 3: Waste Generation, 2012.

•   Urban Climate Change Research Network, Climate Change and Cities: First Assessment Report of the UCCRN (ARC3), Chapter 1: Urban Climate Change in Context, 2011.