Wildfires, waste burning and agricultural burning
Burning practices in agriculture, wildfires, and burning of waste are all sources of black carbon to the atmosphere.
Globally, open burning of fields and forests accounts for approximately 40% of black carbon emissions.1 Emission estimates are however uncertain and regional variations are considerable. Emissions are generally lower in the EU and Southern Cone countries that have adopted no-burn methods in agriculture, while large emission remain in sub-Saharan Africa, Asia and the former Soviet states.
In the Arctic countries, burning in the agricultural sector, including wildfires that spread from set agriculture and forestry fires, is the largest source of black carbon reaching the Arctic.
Wildfires are a natural part of the boreal system but have increased in intensity in recent years due to higher temperatures and dryer conditions.2 Furthermore, as human activity continues to expand into wilderness areas, the accidental ignition of wildfires is becoming more common. For example, approximately half of all wildfires in Canada are human-caused, while nearly 95% of fires in Europe are caused by people.3 Emissions from wildfires are not included in national inventories, but work is proceeding to better capture the proportion of wildfires arising from set agriculture fires as opposed to “natural” causes such as lightning strikes or other sources (even these are exacerbated by the drier conditions appearing under global warming).
Soot from wildfires can spread far from the burning site. A study of the Siberian wildfires in 2012 showed that about one fourth of the huge emissions of black carbon from these fires were transported across the Polar Circle into the Arctic.4 In the summer of 2019, NASA could show how the large number of wild fires – over one hundred – contributed significantly to black carbon in the Arctic atmosphere, in addition to large emissions of carbon dioxide.5 In June 2019, Arctic wildfires emitted 50 megatons of CO2, equivalent to Sweden's total annual emissions and more than the past eight Junes combined.6 Smoke from wildfires is also a serious health problem when it reaches populated areas.
Fires that affect boreal peatlands tend to smolder, which produces more particulate matter emissions compared to open fires. An important concern is that the draining of wetlands and accelerated climate change is shifting the fire regime in way that could turn boreal peatlands in into a net source of carbon dioxide instead of them serving as a carbon sink.7 In addition, burning peatlands release emissions of methane, as well as causing greater thaw of permafrost. A greater proportion of wildfire-mediated permafrost thaw occurs through abrupt ’thermokarst‘ processes that also release a greater proportion of methane, which causes a feedback system to warm the climate faster and further.
While emissions from wildfires are difficult to control, proper management of wildfires is possible and important, not only for reducing emissions of black carbon but also for preventing loss of natural resources and property. For example, frequent, low intensity fires can reduce forest fuel loads and prevent larger, more intense fires in the future. Earlier fire-exclusion policies lead to accumulation of fuels, which has contributed to high intensity fires and thus to the extreme fires in the past decade. Furthermore, low intensity fires are far less likely to inject black carbon into the stratosphere where it is more easily transported to the Arctic.8
The specifics of managing wildfires vary depending on local conditions, such as ecosystem health, climate and weather patterns, access to wildfire sites, and proximity of people and infrastructure. Some general lessons have nevertheless been drawn. In its 2019 report, the Arctic Council Expert Group on Black Carbon and Methane issued the following recommendations for better management:
- Build and maintain international mutual aid and resource exchange arrangements amongst Arctic nations that have specialized experience in wildfire management, suppression, and monitoring.
- Develop region-specific public education campaigns on wildfire prevention and safety.
- Develop and implement regionally appropriate forest management practices that reduce the risk of severe wildfires.
- Use the best available science to develop prediction models that can be used to examine fire risks at daily to decadal scales, to support drafting of prevention and emergency response plans.9
Emission of black carbon from burning of waste is a problem in communities that lack proper waste management or when waste dumps catch on fire. Such burning not only releases black carbon but also known carcinogens, including dioxins and furans. Preventing these emissions require better waste management practices as well as outreach and information to individual households.10
The Arctic Council’s Sustainable Development Working Group (SDWG) in cooperation with the Arctic Contaminants Action Program (ACAP) is currently undertaking a scoping study on solid waste management in the Arctic aimed at providing information about best practices for small and remote Arctic community. Preliminary results indicate that best practices include safer waste burning policies and strict procedures; landfill access control, mandatory collection programs; landfill and equipment maintenance; safe handling of hazardous and other harmful wastes; use of available regional special waste facilities and programs; and, program design based on community behavior and values (including enforcement, education and setup).11
Among Arctic States, biomass burning in agriculture is the single largest source of black carbon emissions when the origin of the fire is used as the measure of categorization. Russia is the largest source country, especially when wildfires spreading from set fires in Siberia are included, and account for about 45% of the total. The Nordic countries, like the EU, have about 10% the levels of Russia; the U.S. and Canada, which allow “permitted” burning, have about 20% of Russia.12 Current emissions inventories tend to include only burning of four primary grains (wheat, rice, soy and barely) as “agricultural burning”; making this source seem erroneously small compared to others. However, in reality the use of fire in the agricultural sector is much broader. In the Arctic region, it includes burning of canola and other kinds of crop stubble; use of fire to clear lands, especially previous cultivated plots in northwestern Russia; burning of pasturelands; and use of fire to clear understory prior to harvest in the forestry sector (not to be confused with wildfire control). In some Arctic Council Observer States the open burning of agricultural waste is an even larger source of black carbon.
In several Arctic countries, emissions from agricultural have been successfully reduced through a combination of awareness campaigns and regulations, such as bans on use of fire including for pasturelands or clearing, or burning of forest residue. All of these uses of fires do have cost-effective alternatives. In some cases, such as burning of crop stubble, alternatives practices save costs. This is because burning destroys soils structure and nutrients, increasing the use of fertilizers by about 25-35% (depending on crop and underlying soil conditions). The brittle nature of burned soil also leads to greater erosion and run-off of fertilizers into nearby water systems.13 Once farmers understand the lower cost (due to decreased need for fertilizer and also less need for petrol with decreased need to work the fields), adoption of no-burn methods tends to spread – though occurs more swiftly with some level of economic support or subsidies, together with effective regulation and in concert with farmer extension services and where needed, initial economic support. A ban on field burning is currently part of cross compliance under EU’s Common Agricultural Policy thus affecting all Arctic States and Observer States following EU law. 14
Arctic Council. (2019). Expert Group on Black Carbon and Methane. Summary of Progress and Recommendations 2019. Retrieved from Arctic Council Secretariat website: http://hdl.handle.net/11374/2411
Bodin, S., Nordberg, L., Pearson, P., & Pettus, A. (2013). On thin ice. How cutting pollution can slow warming and save lives. Retrieved from World Bank website: http://documents.worldbank.org/curated/en/146561468180271158/Main-report
Bond, T. C., Doherty, S. J., Fahey, D. W., Forster, P. M., Berntsen, T., DeAngelo, B. J., … Zender, C. S. (2013). Bounding the role of black carbon in the climate system: A scientific assessment. Journal of Geophysical Research: Atmospheres, 118(11), 5380–5552. https://doi.org/10.1002/jgrd.50171
Open Burning. (n.d.). Retrieved December 10, 2019, from http://openburning.org/
Gramling, C. (2019, August 2). The Arctic is burning and Greenland is melting, thanks to record heat. Retrieved September 17, 2019, from Science News website: https://www.sciencenews.org/article/arctic-burning-greenland-melting-thanks-record-heat
International Cryosphere Climate Initiative (ICCI). (n.d.). Open Burning. Retrieved September 17, 2019, from http://iccinet.org/open-burning/
Kelly, R., Chipman, M. L., Higuera, P. E., Stefanova, I., Brubaker, L. B., & Hu, F. S. (2013). Recent burning of boreal forests exceeds fire regime limits of the past 10,000 years. Proceedings of the National Academy of Sciences, 110(32), 13055–13060. https://doi.org/10.1073/pnas.1305069110
Konovalov, I. B., Lvova, D. A., Beekmann, M., Jethva, H., Mikhailov, E. F., Paris, J.-D., … Andreae, M. O. (2018). Estimation of black carbon emissions from Siberian fires using satellite observations of absorption and extinction optical depths. Atmospheric Chemistry and Physics, 18(20), 14889–14924. https://doi.org/10.5194/acp-18-14889-2018
Masrur, A., Petrov, A. N., & DeGroote, J. (2018). Circumpolar spatio-temporal patterns and contributing climatic factors of wildfire activity in the Arctic tundra from 2001–2015. Environmental Research Letters, 13(1), 014019. https://doi.org/10.1088/1748-9326/aa9a76
Patel, K. (2019, July 31). Arctic Fires Fill the Skies with Soot. Retrieved September 17, 2019, from NASA Earth Observatory website: https://earthobservatory.nasa.gov/images/145380/arctic-fires-fill-the-skies-with-soot
Pearson, P., Bodin, S., Gittelson, A., Kinney, S., McCarty, J. L., Stevenson, G., & Albertengo, J. (2015). Fire in the Fields: Moving Beyond the Damage of Open Agricultural Burning on Communities, Soil, and the Cryosphere. https://doi.org/10.13140/RG.2.1.3691.9126
Sustainable Development Working Group. (2019). Best waste management practices for small and remote Arctic communities. A study of best waste management practices used in remote Arctic communities in Alaska, Canada, and Finland. Retrieved from Sustainable Development Working Group, Arctic Council website: https://www.sdwg.org/activities/sdwg-projects-2017-2019/solid-waste-management-in-small-arctic-communities/
1 International Cryosphere Climate Initiative (ICCI), “Open Burning,” accessed September 17, 2019, http://iccinet.org/open-burning/; T. C. Bond et al., “Bounding the Role of Black Carbon in the Climate System: A Scientific Assessment,” Journal of Geophysical Research: Atmospheres 118, no. 11 (2013): 5380–5552, https://doi.org/10.1002/jgrd.50171.
2Arif Masrur, Andrey N. Petrov, and John DeGroote, “Circumpolar Spatio-Temporal Patterns and Contributing Climatic Factors of Wildfire Activity in the Arctic Tundra from 2001–2015,” Environmental Research Letters 13, no. 1 (January 2018): 014019, https://doi.org/10.1088/1748-9326/aa9a76; Ryan Kelly et al., “Recent Burning of Boreal Forests Exceeds Fire Regime Limits of the Past 10,000 Years,” Proceedings of the National Academy of Sciences 110, no. 32 (August 6, 2013): 13055–60, https://doi.org/10.1073/pnas.1305069110.
3Arctic 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.
4Igor B. Konovalov et al., “Estimation of Black Carbon Emissions from Siberian Fires Using Satellite Observations of Absorption and Extinction Optical Depths,” Atmospheric Chemistry and Physics 18, no. 20 (October 17, 2018): 14889–924, https://doi.org/10.5194/acp-18-14889-2018.
5Kasha Patel, “Arctic Fires Fill the Skies with Soot,” NASA Earth Observatory, July 31, 2019, https://earthobservatory.nasa.gov/images/145380/arctic-fires-fill-the-skies-with-soot.
7Arctic Council, “Expert Group on Black Carbon and Methane. Summary of Progress and Recommendations 2019.”
10“Open Waste Burning Prevention,” Climate & Clean Air Coalition, accessed September 18, 2019, https://www.ccacoalition.org/en/activity/open-waste-burning-prevention.
11Arctic Council, “Expert Group on Black Carbon and Methane. Summary of Progress and Recommendations 2019”; Sustainable Development Working Group, “Best Waste Management Practices for Small and Remote Arctic Communities. A Study of Best Waste Management Practices Used in Remote Arctic Communities in Alaska, Canada, and Finland” (Sustainable Development Working Group, Arctic Council, 2019), https://www.sdwg.org/activities/sdwg-projects-2017-2019/solid-waste-management-in-small-arctic-communities/.
12Svante Bodin et al., “On Thin Ice. How Cutting Pollution Can Slow Warming and Save Lives” (Washington DC: World Bank, 2013), 79–80, http://documents.worldbank.org/curated/en/146561468180271158/Main-report.
13Pam Pearson et al., “Fire in the Fields: Moving Beyond the Damage of Open Agricultural Burning on Communities, Soil, and the Cryosphere,” 2015, https://doi.org/10.13140/RG.2.1.3691.9126.
14Arctic Council, “Expert Group on Black Carbon and Methane. Summary of Progress and Recommendations 2019.”