The Warsaw Summit on Black Carbon and Other Emissions from Residential Coal Heating Stoves and Combined Cooking + Heating Stoves, was held May 29-30, 2017. It was convened by the Climate and Clean Air Coalition, the International Cryosphere Climate Initiative, the Global Alliance for Clean Cookstoves, and the Polish Ministry of the Environment. This document is a summary of the knowledge gaps, challenges, and next steps identified by participants in a series of white papers developed for the summit, at the summit, and in correspondence after the summit.
1. Knowledge Gaps and Challenges:
1.1 Fuels and fuel poverty
There is a clear need to collect more data to understand the quantities of various fuels being used, by country, in residential cooking and heating stoves. Household surveys will sometimes identify which fuels are used but often not the volume or energy content of each type of fuel. Additionally, many households use multiple fuels, or multiple fuels within a given stove, and data should better reflect this reality. There is also a need for better data on fuel preparation and sizing. There was discussion about the labels sometimes applied to fuels and technologies, such as “clean,” “dirty,” or “transitional,” and a suggestion was made to apply these labels to combustion conditions and practices, rather than fuels themselves.
There is a need to better understand and model health and economic impacts of chronic underheating, with the recognition that improved insulation can dramatically reduce the need for extra heating and can also reduce emissions. Addressing chronic underheating was seen as an integral part of a strategy to reduce black carbon (BC) emissions, though in some places households may generate more BC if and when they are able to satisfy their heating needs.
As with fuels, there is a need to improve data related to stove usage patterns, including especially stove used for such end uses as water heating and income-generating activities. When assessing usage, it was emphasized that factors such as cultural practices, local conditions, and level of economic development should be documented and taken into account. There is also a need to recognize the complexity of multi-stove homes (where there might be several stoves present, potentially of different ages and used for different functions).
1.3 Emissions and emission factors
There is a need for data to collect and publicize emission factors for all relevant stove emissions, including SOx, CO2, and heavy metals—as well as PM2.5, BC and NOx. This would allow for comparison of BC emissions from wood, coal and pellet stoves. Pellet stoves may emit very little BC, but this needs to be confirmed. Emission factors for domestic coal stoves, for example, can be highly variable, and are influenced by factors such as coal quality, size of coal pieces, and user behavior. Relatedly, there is a need to better document BC reductions relative to PM2.5 reductions.
1.4 Baseline estimates and projections
Building on the need for better data on fuel use, stove use, and emissions, there is a need to better understand the magnitude of emissions by stove use category and fuel type. Having this understanding would allow better analyses of health impacts, climate impacts, and other environmental impacts, as well as development and prioritization of appropriate and effective mitigation approaches. However, it was noted that it is not necessary to reduce uncertainties in our understanding of the current situation (i.e. present day emissions and impacts) in order to understand mitigation potential.
Projections of future household fuel demand and its specific structure have often been overly simplistic. Coordinated upscaling, from local experiences to regional or international assessment, must be done better, including documenting and communicating the methods used for making assumptions in this process. It will be necessary to critically examine the constraints and time-lag aspects of fuel and stove shifts, as well as the consequences of proposed actions to change fuel use and associated emissions. With improved projections of household fuel demand, there would be higher capacity to develop detailed mitigation projections.
1.5 Systems approach
There was discussion of the need to employ a “systems approach” to thinking about fuel use and stoves. Specifically, there was broad agreement that a “household system” approach is needed, incorporating users, fuels, stoves, home insulation, and other facts, when designing new stoves or creating intervention, such as stove changeout initiatives. The following schematic equation was suggested: FTAH = fuel, technology, application (or end use) and human factor/impacts. In further refining this idea, two systems were proposed: 1) a stove-fuel-operating practice system, and 2) the entire household system. More broadly, participants conceptualized two overlapping systems: 1) the household/local economic system, and the 2) larger national/global energy/climate system. It was noted that different perspectives on approaches to improving residential emissions emerge depending on which system is prioritized.
1.6 Health impacts
In terms of health impacts from the use of the stoves, it was noted that better communication of health impacts and toxins in fuels is necessary. Specific to coal, participants highlighted that Improving coal combustion conditions will not reduce emissions of toxic elements sometimes found in coal and of concern to human health (such as sulfur, mercury, arsenic, lead), although regulation and careful labeling of coal marketed to consumers, could possibly minimize some risks, though It probably would not be feasible in some markets.
1.7 Stove Producer landscape
It was noted that stove producers can help collect and analyze data and trends in annual sales of coal stoves or wood heat/cook stoves, by country. Also, emission standards can consolidate industry and either drive small producers out of business or into a grey economy, creating a community that can absorb stricter emission standards.
1.8 Testing standards
Testing standards are not currently well-designed to allow stove comparison, even at basic levels (for PM2.5, for example), let alone for more complicated pollutants such as black carbon or carbon monoxide. It will be important to establish a standard test method for stove, by type of stove (heating, cooking, etc.), to make sure stoves with reliable performance are installed.
It was noted that test methods should capture “real operation cycles of use,” including ignition. There are few existing testing standards; and they are not aimed sufficiently at actual emissions and consumer use (missing ignition especially). It would be helpful to collect and analyze existing final or draft fueling and testing protocols to determine what is being measured in these protocols. Participants were interested in finding out whether there are coal emission testing standards for stoves anywhere in the world.
1.9 Regulations and Enforcement
There is a need for sharing best practices around enforcement of regulations and standards, including effective market surveillance, and action against illegal or incorrect burning practices.
2. Next Steps toward Solutions:
2.1 Heating fuel and technology surveys
Both the World Health Organization (WHO) and World Bank will work to improve heating data collection and data tracking. The WHO is already engaged in a process to update nationally-representative surveys to include more questions about household fuel use, including household heating behavior. It was suggested that existing heating-related surveys should be shared across institutions. Current household surveys should be amended to include multiple uses, as well as the concepts embedded in the proposed “household system” perspective.
2.2 Fuels database
Participants recommend the creation of a curated fuel use and fuel quantity database, to track changes in fuel use and fuel quantities used for cooking and heating.
2.3 Emission inventories
Emission inventory estimates should be improved, by drawing on new heating survey data., such as that which will be collected through nationally-representative surveys being updated by the WHO. Participants recommended producing a map or chart showing which countries have the highest per capita use of coal heating or combined cooking/heating stoves, for the purpose of communicating the issue to government entities.
2.4 Stove design
There was interest in spreading stove design solutions, after stove emission testing had been replicated and results compared to other stove designs. It was noted that new stove designs need to pass safety standards testing as well. Solutions should include good environmental and health-related performance, whether that be in the stove dimensions and design, or the fuel. It was noted that eliminating consideration of specific fuels such as coal may suppress innovation and may not result in desired results, given the ubiquity of coal use in some regions and biomass use worldwide; however, use of coal in households runs counter to the WHO’s strong recommendation, in the Indoor Air Quality Guidelines, against any use of unprocessed coal in households. Participants noted that some stove designers have not respected the need for robust solutions that deliver good environmental performance under the expected range of fuel and operation conditions, so some stoves do not deliver health benefits.
2.5 Stove testing
Accepted and robust “field” or “real world” testing methodologies, such as those underway under Working Group 3 (Field Testing Methods) of the International Organization for Standardization (ISO)/Technical Committee (TC) 285 (Clean cookstoves and clean cooking solutions), should be developed. Testing protocols should be shared and spread. Testing protocols should be separated from government regulation. It would be useful to create a database of information gained from stove tests, including which technologies meet particular standards. There was a particular interesting in comparing BC emissions among wood, pellet, and coal stoves. Participants asked to consider requiring multiple labs to test a single stove to ensure consistency. Stove type (radiant heating or water heating), fuel type (raw coal, briquette coal, biomass), operation, and other factors should be included in a given test method. Participants emphasize the need to reconcile any discrepancies between lab testing and field testing.
2.6 Communication and networking
There was strong support for creating a network of people working on combined cooking and heating stoves, including summit participants. One goal would be to spread information about the importance and role of combined stoves in emissions creation and reduction. It was suggested that the summit website could be maintained as a networking and information sharing site. There was also support for creating a platform for technology sharing and development, especially low-cost stove models. The World Bank has since provided access to a collaborative platform to encourage communication on this topic.
2.7 Funding and finance
It was suggested that it is important to engage major donors and foundations in tackling the issues raised at the summit. In addition, there is a need to aid countries and stakeholders in mobilizing existing financing mechanisms. The World Bank expressed interest in engaging major donors on the topics of coal heating and combined cooking/heating stoves.
2.8 Stove Producers
There is a need to “map” and then engage major stove producer networks. It was suggested to create a catalog of producers by stove type, sales amount, power level, fuel type, etc.
Participants raised the need to promote further research into social acceptance of stoves, and stove/fuel needs. This includes integration of the systems approach to household fuel use and stove use detailed in Section 1.5, including more distal aspects of the household system, such as weatherization, fuel stacking, energy end uses beyond cooking and heating, and policy-driven energy use changes.
2.10 Fuel switching
It will be necessary to develop criteria for fuel switching programs (with the notion that people can change) and think long-term (“zero net” planning). Longer term, the need for switching to renewable energy sources is needed, though now there is a strong emphasis on transitional stoves. Fuel switching should lead to improvement in air quality (reduction of PM) and health outcomes (improved quality of life) and climate change (reduction of BC).
Participants advocated for developing a model coal “burn right” campaign. There is a need to emphasize the health effects of solid fuel heating in campaigns, as health can be a strong motivator in fuel switching or improving burn techniques.
2.12 Reduce emissions from stoves (cooking or heating)
Promoting and prioritizing insulation of homes is important, as a way to reduce fuel use and emissions and improve quality of life. District heating should also be considered. To accomplish emission reductions, combustion conditions should be improved. Efforts to improve combustion efficiency should go hand-in-hand with efforts to improve efficiency of home heating (stove product or home improvements). As the transition to renewable energy occurs, approaches to improve efficiency of existing fuel use could potentially reduce air pollutants, including BC, and protect health. There is a need for systems analysis of climate (BC reduction) and health benefits of a combined approach to a) repairing leaking stoves, b) improved home insulation, and c) improved efficiency /reduced emission coal stoves (in this priority order).
2.12 Regulation and labeling
There is a need to create model standards/policies/regulations. It was suggested that a voluntary ecolabelling scheme could be effective. Participants want to confirm whether EU countries must adopt coal emission standards for stoves in 2022, including whether Poland will introduce those standards in 2019. It was mentioned that, for long-term efficacy of labeling, legislation could be referenced in eco-label requirements for stoves.