Wood has a long tradition as a local source of fuel for domestic heating, but wood burning unfortunately also contributes to black carbon emissions. Approximately one fifth of black carbon emissions in the Arctic come from domestic heating, with significant variation between different countries and generally higher emissions in the Nordic countries.1 However, with modern stove technologies, emissions of black carbon can be significantly reduced, while still using wood as fuel.2 Emission can also be reduced by using proper techniques for lighting and burning fires. Both measures are important for improving local air quality with immediate health benefits, in addition to the positive impacts in relation to reducing climate impacts from black carbon. It should also be noted in rural locations where wood burning does not cause immediate air quality problems, it can still produce enough black carbon to have climate impacts in the Arctic.3
In some countries coal is also still being used for domestic heating. Due to long-range transport, emissions from coal-heating in homes outside the Arctic are a significant source of black carbon in the region, but more work is required for quantifying its potential impacts.
Technologies, fuel quality, and techniques
Black carbon is formed when wood is burned in high temperature without oxygen, which creates an incomplete combustion.4 Measures to reduce emissions of black carbon are thus aimed at creating better burning conditions. This can be achieved by using modern stoves and boilers that allow for better control of burn conditions than in old appliances. In the past 10-15 years, the use of wood as fuel has increased but the improvement of wood-burning technologies has off-set the potential increase in black carbon emission from domestic heating.5 A major limitation of this option is that replacement of older wood burning stoves is slow. Another limitation is that emissions also depend on how the stove is operated, where incorrect use can lead to much higher emissions. Stoves that use automated systems for supplying fuel and air often have lower emission. To function well, a wood burning stove also needs a well-functioning chimney since the supply of oxygen to the fire depend on the draft provided by the chimney.6
Ensuring good fuel quality is an important concern for reducing black carbon emission from wood burning. Key are the moisture content and the size of the fuel, where homogenized wood fuel like chips or pellets give the best combustion conditions.7
How a fire is lit and maintained has a major influence on emissions. Several projects now focus on teaching techniques for lighting fires.8 A report on residential wood combustion from the Arctic Contaminants Action Program (ACAP) provides the following tips for reducing emissions: use dry firewood; do not install wood-burning stoves with heat outputs higher than the actual space heating requirement to avoid sub-nominal heat output; use top-down kindling techniques when lighting the stove from cold conditions which can reduce emission by 30–50 per cent; do not burn anything but dry wood; and follow the instructions in the operating manual provided by the wood stove producer, specifying the amount and time intervals for reloading.9
In order to achieve the goal of heating and keeping buildings warm, other options for reducing emissions of black carbon include measures and technologies that are not related to the wood burning as such. They include better insulation of buildings as well as using alternative or complementary heating options, such as solar and districts heating.
Policies and incentives
Regulations of residential heating is mainly a national and sometimes local responsibility. Examples of measures in the Arctic countries are environmental performance standards, emission limits, appliance certification and eco labels for new biomass combustion appliances; programs to replace inefficient existing appliances; education campaigns; improving energy efficiency of buildings; and temporary bans on using high pollutant combustion appliances due to poor air quality. However, further work is needed to reduce emissions from domestic heating and the Arctic Council Expert Group of Black Carbon and Methane has issued the following recommendations:10
Actions to reduce emissions from new biomass combustion appliances
- Develop and adopt, where possible, a standardized testing protocol for black carbon emissions for new heating appliances;
- Promote energy efficiency standards – voluntary or regulatory – for new heating appliances and other clean sources of space heating. Appliances that produce heat more efficiently generally use less fuel and generate fewer emissions of particulate matter;
- Promote emission performance standards for new residential wood combustion appliances;
- Cooperate with manufacturers to promote and bring to market affordable designs and technologies that improve biomass combustion appliance use, reduce operator error and thereby reduce black carbon emissions;
- Develop, test and deploy effective education campaigns to improve consumer use of all biomass combusting appliances.
Actions to reduce emissions from legacy biomass combustion appliances
- Incentivize the replacement of older biomass combustion appliances with cleaner and more efficient alternatives, including cleaner biomass combustion appliances, while adopting policies to keep legacy heating appliances from reaching the second-hand market;
- As with new stoves, developing, testing and deploying effective education campaigns to improve consumer use of biomass combustion appliances is necessary to reduce emissions associated with operator error.
Actions to reduce emissions by promoting enhanced home heating efficiency
- Adopt mandatory or voluntary standards for building energy efficiency;
- Offer financial incentives for building energy efficiency such as tax credits, rebates, or financing for high-usage stoves.
Further policy options
The soon-to-be published EUA-BCA report Enhancing the reduction of black carbon emissions to protect the Arctic: Mapping the policy landscape of national, regional and international action elaborates further on the opportunities and challenges for reducing emissions from this sector, where emissions from small-scale domestic heating are one of the most important sources of black carbon within the Arctic region and where emissions are diffuse and caused by private households or small local boilers for district heating. The control of these emissions is demanding: households are not under direct regulation and control of agencies, and cost-effectiveness in terms of emission reduction is not a central driver of decisions. What matters is the access to fuel and assurance of comfortable use.
Important actions, considering the special features of the area, include:
- Enhance the international exchange of experience in providing economic incentives to replace old heating equipment and disseminating information on the benefits and techniques of “burn right”
- Incentivising energy efficiency improvements in buildings
- Encourage countries to set higher emission requirements on stoves and boilers as well as phase out the old ones in use.
The actions differ from those identified for several other sectors in emphasising the role of individual households and local communities. Studies have identified the importance of correct fuel handling and operation and maintenance of stoves, fireplaces or boilers. If this information is fully taken up by households, emissions could be reduced significantly. Changes in practice are notoriously difficult to accomplish, but for example chimney sweepers can act as ‘fireplace consultants’ providing hands-on information to households. As an alternative or complementary measure, one can also provide targeted information through fuel providers, with step-by-step instruction pamphlets. Outside the behavioural change interventions, it is also important to further consider the use of technology-specific economic incentives (investment subsidies or scrapping rewards) or even restricting the use of obsolete technologies.
As examples of conceptually suitable policy processes, the EU has legislation directly addressing emissions from small-scale domestic heating under the framework of the EU Ecodesign Directive. The Arctic Council ACAP has supported actions that aim at reducing emissions from residential wood combustion and Nordic funding has been directed to reduce emissions from local district heating boilers. These demonstration activities are essential in developing the awareness base for wider policy and legislative change. Further, both national and international economic incentives have been employed for the renewal of local district heating to improve both local air quality and energy efficiency.
Details on different options reducing emission from domestic heating are described in the report Elements in the policy landscape for action on black carbon in the Arctic: Supporting material to the EUA-BCA report Enhancing the reduction of black carbon emissions to protect the Arctic.
AMAP. “Arctic Climate Issues 2015: Short-Lived Climate Pollutants (Summary for Policy-Makers),” 2015. http://www.amap.no/documents/doc/summary-for-policy-makers-arctic-climate-issues- 2015/1196.
Arctic Contaminants Action Program (ACAP). “Reduction of Black Carbon Emissions from Residential Wood Combustion in the Arctic. Black Carbon Inventory, Abatement Instruments and Measures.” Technical Report. Arctic Contaminants Action Program (ACAP), 2014. https://oaarchive.arctic-council.org/handle/11374/388.
Arctic Council. “Expert Group on Black Carbon and Methane. Summary of Progress and Recommendations 2019.” Tromsø, Norway: Arctic Council Secretariat, 2019. http://hdl.handle.net/11374/2411.
International Cryosphere Climate Initiative (ICCI). “Woodstoves and Cookstoves.” Accessed October 9, 2019. http://iccinet.org/woodstoves-and-cookstoves/.
1 AMAP, “Arctic Climate Issues 2015: Short-Lived Climate Pollutants (Summary for Policy-Makers),” 2015, http://www.amap.no/documents/doc/summary-for-policy-makers-arctic-climate-issues- 2015/1196; Arctic Council, “Expert Group on Black Carbon and Methane. Summary of Progress and Recommendations 2019” (Tromsø, Norway: Arctic Council Secretariat, 2019), http://hdl.handle.net/11374/2411. AMAP, “Arctic Climate Issues 2015: Short-Lived Climate Pollutants (Summary for Policy-Makers).”
2 International Cryosphere Climate Initiative (ICCI), “Woodstoves and Cookstoves,” accessed October 9, 2019, http://iccinet.org/woodstoves-and-cookstoves/.
3 Arctic Contaminants Action Program (ACAP), “Reduction of Black Carbon Emissions from Residential Wood Combustion in the Arctic. Black Carbon Inventory, Abatement Instruments and Measures.,” Technical Report (Arctic Contaminants Action Program (ACAP), 2014), https://oaarchive.arctic-council.org/handle/11374/388.
4 Arctic Contaminants Action Program (ACAP).
5 Arctic Council, “Expert Group on Black Carbon and Methane. Summary of Progress and Recommendations 2019.”
6 Arctic Contaminants Action Program (ACAP), “Reduction of Black Carbon Emissions from Residential Wood Combustion in the Arctic. Black Carbon Inventory, Abatement Instruments and Measures.”
7 Arctic Contaminants Action Program (ACAP).
8 International Cryosphere Climate Initiative (ICCI), “Woodstoves and Cookstoves.”
9 Arctic Contaminants Action Program (ACAP), “Reduction of Black Carbon Emissions from Residential Wood Combustion in the Arctic. Black Carbon Inventory, Abatement Instruments and Measures.”
10 Arctic Council, “Expert Group on Black Carbon and Methane. Summary of Progress and Recommendations 2019.”