Black Carbon: A Key Climate Pollutant

Understanding black carbon emissions and the strategies to reduce them—one of the fastest ways to slow near-term climate change.

What is Black Carbon?

Black carbon (BC), often called "soot," is a fine particulate matter produced by the incomplete combustion of fossil fuels, biofuels, and biomass. It consists of tiny, light-absorbing carbon particles.

Unlike CO₂, black carbon is a short-lived climate pollutant lasting days to weeks in the atmosphere. It contributes significantly to global warming by:

  • Absorbing sunlight and heating the atmosphere
  • Depositing on snow and ice (e.g., in the Arctic or Himalayas), darkening surfaces and accelerating melting

It is estimated to be the second- or third-largest contributor to human-induced warming after CO₂, while also causing millions of premature deaths annually due to air pollution.

Major Sources of Black Carbon

Black carbon emissions come primarily from:

Residential Cooking & Heating

Traditional biomass or coal stoves in developing regions

Diesel Vehicles

Trucks, buses, and off-road machinery

Industry

Brick kilns, coke production

Open Burning

Agricultural waste and wildfires

Gas Flaring

Oil and gas operations

Shipping

Heavy fuel oil combustion

Climate and Health Impacts

Rapid Warming

Black carbon has a warming effect 200-2,000 times stronger than CO₂ on a per-molecule basis, making it a critical short-term climate target.

Polar Amplification

Deposits on snow and ice reduce reflectivity, accelerating melting in the Arctic and high-altitude regions.

Air Quality & Health

Black carbon particles penetrate deep into lungs, causing respiratory diseases, heart disease, and premature death.

Agricultural Impact

Reduced sunlight from atmospheric BC and snow darkening affects crop productivity.

How to Reduce Black Carbon Emissions

Reducing black carbon is one of the fastest ways to slow near-term climate change, with co-benefits for health and agriculture. Many strategies use existing, cost-effective technologies and could cut emissions by up to 80% globally.

Targeted actions could avoid ~0.1–0.2°C of warming by mid-century while saving lives and improving air quality.

Key Mitigation Strategies by Sector
SectorMain StrategiesBenefits
Household EnergySwitch to clean fuels (LPG, electricity) or advanced clean cookstovesDramatically reduces indoor pollution and BC emissions
TransportInstall diesel particulate filters (DPFs); enforce low-emission standards; promote electric vehiclesHighly effective; proven in regions like California
IndustryUpgrade to efficient designs (e.g., zigzag kilns for bricks)Significant reductions in high-emission areas like South Asia
OtherBan open agricultural burning; eliminate gas flaring; restrict heavy fuel oil in shippingProtects sensitive regions like the Arctic
How You Can Help

As a Black Carbon Expert volunteer, you can:

  • Research and document BC emission sources in your region
  • Advocate for clean cookstove programs and emission standards
  • Support organizations like the Climate and Clean Air Coalition
  • Educate communities about BC health and climate impacts
  • Participate in policy advocacy for emission reduction targets
Additional Resources

Climate and Clean Air Coalition: Global initiative promoting BC reduction

UNEP Reports: Comprehensive assessments on BC emissions and mitigation

WHO Guidelines: Health impacts and air quality standards

National Programs: Country-specific BC reduction initiatives and targets

Questions or Need Help?

Connect with our Black Carbon Expert team:

Email: [email protected]

Slack: #black-carbon channel

Office Hours: Wednesdays & Fridays, 3-5 PM UTC