Soot: another path to climate action… if we take it

What’s the best way to slow climate change? Governments have mostly wasted the last twenty years, conspicuously failing to effectively reduce the greenhouse gases in the Kyoto Protocol basket ( CO2, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulphur hexafluoride). Maybe we can do better on soot – also known as particulate air pollution, which is easier and cheaper to control.

Recent research shows that soot plays a significant role in global climate systems.  It has been linked to changes in cloud cover, dust storms, and forest fires (especially in the boreal forest) as well as both global and regional climate effects including Arctic warming, Himalayan glacier melt, and changes in monsoon patterns. For a survey of this research, see, for example, V. Ramanathan, & G. Carmichael “Global and regional climate changes due to black carbon” (2008) 1 Nature Geoscience 221.

Another attribute of soot that has attracted attention is its short lifecycle and the corresponding opportunity to see much faster reductions in climate forcing following a reduction in soot emissions (as compared to reductions in the long-lived Kyoto basket gases). Soot is removed from the atmosphere by wet removal and direct deposition in as little as one week . This is in contrast to the gases in the Kyoto basket which have a lifetime of at least 2 years and carbon dioxide, which has a lifecycle of 100 years or more


Earlier this month, Canada joined the Global Alliance for Clean Cookstoves. The aim of the initiative is to provide efficient cookstoves to people who are reliant on biomass stoves and open fires for cooking and heating.  They hope to support the adoption of clean cookstoves and fuels in 100 million households by 2020.


What’s missing from this announcement about soot reduction is what Canada will be doing at home. As illustrated in the charming video produced for Ecojustice’s Stop Soot Campaign, soot is the second leading cause of arctic warming and tighter standards on diesel fuel would help to reduce this impact.

by Meredith James and Dianne Saxe



  1. Cathy Baiton

    The United Nations Environment Program's 2011 report on the importance of short-lived climate forcers in accelerating climate change also targets both wood burning and diesel vehicles as two of the biggest sources of black carbon in Europe and North America.

    The UN's recommendations include replacing wood-burning stove technologies currently used for residential heating in industrialized countries with pellet-burning systems. Measures such as phasing out wood-burning stove use, and the banning of open burning, are essential, for both the climate and human health. And as the report explains, such actions would yield benefits both globally and regionally.

    Now that Canada's federal government has joined the international initiative aimed at reducing harmful pollutants like black carbon/soot, everything possible should be done to help see that the UN recommendations for wealthy nations are implemented in Canada.

    A pdf summary of the report and the UN's recommendations is available here:

Leave a comment:


Required field