Black carbon, or soot, is one of the super pollutants alongside methane that are responsible for half of global warming. Beyond climate change, it also pollutes the air, contributing to 8 million premature deaths and the trillions of dollars of economic cost (5% of global GDP) from air pollution each year.
Cutting emissions from major black carbon emitting sectors can be one of the quickest and most cost-effective ways to make progress on climate goals and improve people’s health, helping billions breathe cleaner air and boosting economies. That’s why we need fast, targeted global and local action black carbon on top of existing decarbonisation, methane and air pollution reduction efforts.
What are some of the best solutions to reduce black carbon emissions?
Black carbon is emitted alongside other gases and pollutants across a range of economic sectors, from transport to household energy. Given black carbon’s unique position at the intersection of climate and health, using black carbon as a lens can help us to identify which actions or policies within each sector will reap the greatest benefits for air quality and near-term climate action. Some of these solutions might otherwise be overlooked.
For instance, within the transport sector, it is particularly effective to reduce black carbon emissions from agricultural and construction machinery (or non-road mobile machinery), which emit a growing proportion of total black carbon and air pollution emissions. Solutions include electrification of machinery, retrofit schemes for old machinery still in use and introduction of off-road emissions standards. City- and state-level policymakers can achieve this by updating their procurement policies and rolling out clean construction zones.
Cleaning up the fuels used in Arctic shipping is another effective intervention in the transport sector. When black carbon settles on snow or ice, it darkens the surface, reducing its reflectivity and causing it to absorb more solar energy. This accelerates melting, further reducing its ability to deflect heat in a dangerous feedback loop that increases warming across the globe. The Arctic ice pack has already retreated to historically low levels and continues to shrink at alarming rates. Its darkened surface is only accelerating this.
Black carbon emissions in the Arctic nearly doubled between 2015 and 2021, and a key factor for this is the increasing commercial shipping traffic through the Arctic using highly polluting polar fuels. Solutions include cleaner fuels (referred to as ‘polar fuels’) that can dramatically cut black carbon emissions if adopted broadly in Arctic shipping. Other solutions include increased use of shore power in Arctic ports, promoting use of electric shipping vessels, and establishing emission control areas and green corridors in vulnerable regions to curb black carbon emissions.
Within the residential sector, household heating and cooking using biomass, such as wood, charcoal or dung, is a major source of black carbon emissions. For heating systems, there should be stringent regulations for the sale and use of heaters powered by coal, wood and biomass. Transitioning to clean heating solutions could help significantly reduce black carbon emissions. These solutions include: air source heat pumps; electric radiant, direct contact and convector heating systems; and hybrid systems combining electric and thermal heating systems.
You can explore a range of effective solutions to reduce black carbon emissions in the solutions wheel below. Hover your mouse over a sector for more information on effective interventions tested in different parts of the world.
Recommendations for policymakers
1. Rapid action on black carbon intensive sectors in cryosphere regions, including the Arctic, Himalayas, and Andes regions:
Black carbon accelerates snow and ice melting in a way that is distinct to any other pollutant. Urgent policy and regulatory reforms to rapidly reduce black carbon emissions are essential to protect highly vulnerable cryosphere regions. For instance:
International Maritime Organization (IMO) reforms to address long-standing weaknesses in the regulation of the shipping industry, such as requiring the use of polar fuels, can help to halt the rapid increase in black carbon emissions from international shipping, which heavily impacts the Arctic.
Policymakers and financial institutions should support interventions that accelerate the clean energy transition in the Himalayas and other cryosphere regions, with a core focus on cooking, lighting, and heating, and support the transition to cleaner brick kilns.
2. Prioritise black carbon in clean air and energy policies:
Policies targeting air quality, especially PM2.5, often overlook the distinct benefits of reducing black carbon-rich emissions versus other particulate sources. To maximise climate, health, and environmental gains, policymakers at all levels should prioritise black carbon reduction within clean air and energy policies.
For example, road transport regulations such as the EU’s EURO VI focus on particle number, which is a better proxy for black carbon. Similarly, the Gothenburg Protocol urges parties to target black carbon-rich sources and has the potential to make a major impact through its ongoing revision process by setting ambitious measures for black carbon mitigation. Greater awareness among policymakers and stronger prioritisation of black carbon in clean air and energy strategies are essential for meaningful progress on climate and health.
3. Take coordinated action on super pollutants:
Super pollutants including black carbon are responsible for half of global warming to date and present the world’s best opportunity to secure a near-term ‘win’ against climate change. Policy and decision makers must build on the momentum and progress achieved from a strong focus on methane in recent years and move towards a more integrated and coordinated approach to super pollutants as an issue.
This includes focusing on sectors with high levels of black carbon and other super pollutant emissions, for instance, holistic waste management that reduces both open burning and landfill emissions and the promotion of natural and sustainable agricultural practices that reduce pre-harvest methane emissions and post-harvest crop burning.
At COP30, nine countries made a first-of-its-kind announcement to tackle major sources of black carbon emissions, and to form a peer network for joint advocacy and technical and policy exchange. Governments and other funding bodies can build on this momentum by recognising the urgent need to tackle all super pollutants and commit the funding needed to make progress and deliver holistic solutions.