International effort launched to track black carbon in the Arctic

Scientists estimate that reducing black carbon emissions could reduce warming in the Arctic by about two-thirds over the next thirty years.

The Arctic is warming rapidly, and scientists believe that reducing the amount of black carbon released to the atmosphere will help to slow down climate change. On April 18, 2011 six nations announced that they will collaborate in a new effort to track black carbon in the Arctic in order to develop fast and effective strategies to mitigate the impact of black carbon on climate change. The effort is titled Coordinated Investigation of Climate-Cryosphere Interactions (CICCI), and participants will include scientists from China, Germany, Italy, Norway, Russia, and the United States.

Black carbon (soot) is formed during the incomplete combustion of fossil fuels and biomass. In industrialized nations, black carbon is emitted into the atmosphere when diesel or coal is used for energy production. In developing nations, black carbon is predominately emitted into the atmosphere when biomass is used for cooking and heating homes. Forest fires are a natural source of atmospheric black carbon.

When particles of black carbon fall onto snow and ice in the Arctic, the ground absorbs more incoming solar radiation and melts at a faster rate. Scientists refer to this effect as a decrease in albedo – or surface reflectivity.

In a press release, Tim Bates, a chemist at NOAA’s Pacific Marine Environmental Laboratory and co-lead for the CICCI initiative in the United States, described how black carbon can contribute to warming in the Arctic:

Carbon is dark in color and absorbs solar radiation, much like wearing a black shirt on a sunny day. If you want to be cooler, you would wear a light-colored shirt that would reflect the sun’s warmth. When black carbon covers snow and ice, the radiation is absorbed, much like that black shirt, instead of being reflected back into the atmosphere.

Illustration showing the reflection of sunlight by polar ice that is soot-free (left) and the absorption of sunlight by polar ice that is soot-covered (right). Image credit: NASA

The Arctic is warming at an unprecedented rate. On May 4, 2011, the Arctic Monitoring and Assessment Programme (AMAP) released a comprehensive report detailing the changes that are occurring in the Arctic at a conference in Copenhagen. The AMAP report is titled Snow, Water, Ice and Permafrost in the Arctic (SWIPA).” It was compiled by nearly 200 experts on polar environments.

A key finding of the SWIPA report is that the past six years (2005-2010) have been the warmest period ever recorded in the Arctic, and that these changes in the Arctic are being driven by higher surface air temperatures. Further, the SWIPA report describes how warming of the Arctic may negatively impact people and ecosystems in the Arctic and in areas beyond through events such as melting sea ice, thawing permafrost, loss of wildlife habitat, damage to infrastructure and rising sea levels.

People responded to EarthSky’s earlier coverage of the SWIPA report by asking: what can be done to stop or reverse warming in the Arctic?

Reducing black carbon emissions has been identified by the United Nations Environment Programme (UNEP) as a viable climate change mitigation strategy that could have immediate and multiple benefits for human well-being. Scientists estimate that reducing black carbon emissions could reduce warming in the Arctic by about two-thirds over the next thirty years. Reducing black carbon emissions would benefit the climate quickly because black carbon is relatively short-lived in the atmosphere compared to greenhouse gases.

In addition to benefiting the Arctic, international efforts to reduce black carbon are projected to reduce future global warming by 0.5 oCelsius, prevent 2.4 million premature deaths due to respiratory illnesses and boost the production of crops such as maize, rice, soybean, and wheat.

A sustainable cookstove installed through Peru’s national cookstove program. The small opening that allows only the tips of the fuel to burn makes these improved stoves or “cocinas mejoradas” more efficient and cleaner burning than open fires. Image credit: Ranyee Chiang, AAAS Fellow hosted by U.S. Department of Energy

The 2011 international CICCI initiative will yield important information for shaping future black carbon reduction strategies. Observations of black carbon in the Arctic will be collected from aboard ships, from land-based sites, and from aircraft. These data from CICCI will help to provide accurate measures of how much black carbon is being deposited in the Arctic, where it’s coming from, and how the extra carbon is affecting Arctic ecosystems and contributing to climate warming trends.

Deanna Conners