Black Carbon - Theme, Pufendorf IAS

Theme at the Pufendorf Institute for Advanced Studies

Black Carbon – Formation, life cycle, impacts, co-benefits, policy, mitigation and response measures

This initiative develops a multi- and cross-disciplinary research program centered on soot from domestic and industrial combustion processes. Also called black carbon or elemental carbon, soot is a major driver of climate change and contributor to severe health effects. Bringing together scientists from disciplines in the natural, engineering, medical and social sciences, as well as industrial partners and stakeholder groups, the program seeks significant improvement in scientifically sound policymaking aimed at minimizing the various negative effects of combustion employed in the service of humankind.

Combustion is fundamental to human activity, and is the main supplier of heat, energy and transportation services in all nations today. Most combustion processes are non-optimized and produce soot as a result of hot, air-starved combustion conditions. Once emitted into the air, soot particles can remain airborne for hours to weeks and cause regional-scale harmful effects on climate, air quality and health. Black carbon is identified as a major short-lived climate forcer (SLCF), but the magnitude of its warming effect is still uncertain.

Political responses in terms of legislation, policy, regulation and governance are beginning to emerge, and have not yet had much effect in curbing climate change, air pollution or adverse health effects. Some measures that combine a change in fuels and/or combustion technique have been more successful than others. Recognition of expected co-benefits and synergies among climate mitigation, air pollution abatement, health benefits and ecosystem protection is a motivator for measures to be taken, despite specific uncertainties. Still, black carbon emissions are not directly regulated in regional air pollution agreements or in international climate treaties.

Emissions of black carbon show a tendency to decrease over time in developed nations, but they are still increasing in emerging and transition economies. In less developed regions, domestic cooking is a significant cause of very high soot exposure levels and severe health effects, ranging from indoor to the phenomenon known as the Atmospheric Brown Cloud (ABC) that encompasses a large region in Asia.

Large uncertainties remain regarding the causal chain of events and processes that give rise to the emissions, atmospheric transport, as well as the magnitude and nature of the impacts. At the present level of understanding, there are significant obstacles, including governance and development aspects, to quantifying the benefits of different potential measures to reduce black carbon emissions and their impacts.