The latest science, described in the World Bank report “Turn Down the Heat ,” indicates that we are heading toward a 4° C warmer world, with catastrophic consequences in this century. While carbon dioxide (CO2) is still the No. 1 threat, there is another category of warming agent called short-lived climate pollutants (SLCPs). Mitigating these pollutants is a must if we want to avoid the 4° C warmer future.
The main SLCPs are black carbon, methane, tropospheric ozone, and hydrofluorocarbons. They are potentially responsible for more than one-third of the current warming. Because SLCPs have a much shorter lifetime in the air than CO2; reducing their emissions can create almost immediate reduction of global/regional warming, which is not possible by reducing CO2 emissions alone. According to one U.N. report , full implementation of 16 identified measures to mitigate SLCPs would reduce future global warming by about 0.5˚C.
In this blog, we will focus on one SLCP – black carbon. Black carbon is a primary component of particulate matter (PM), the major environmental cause of premature deaths globally. As a climate pollutant, black carbon’s global warming effects are multi-faceted. It can warm the atmosphere directly by absorbing radiation. When deposited on ice and snow, black carbon reduces their reflecting power and increases their melting rate. At the regional level, it also influences cloud formation and impacts regional circulation and rainfall patterns such as the monsoon in South Asia .
In addition to their warming effects, SLCPs contribute substantially to indoor and outdoor air pollution, with tremendous impacts on health and agriculture. A new analysis of global causes of death  estimates that particulate matter pollution accounted for about 3.1 million deaths in 2010, and indoor pollution from solid fuels for an additional 3.5 million deaths.
South Asia suffers disproportionately from both indoor and outdoor air pollution due to high level of particulate matter. The four countries with the highest air pollution impact on human health  are all in South Asia: India , Bangladesh , Nepal , and Pakistan . It is estimated that in India alone, about 620,000 die every year because of outdoor air pollution. Therefore, reducing SLCPs will not only reduce global warming but will also substantially improve human health.
Brick making is a major source of PM emissions because it uses outdated, inefficient, and highly polluting technologies and coal as the primary fuel in South Asia. For the same amount of coal consumed, Bangladesh, India, and Nepal produce a total of about 300 billion bricks annually, while China produces about 1 trillion bricks. Due to a massive transformation of its brick industry, China produces today more than three times the amount of bricks as Bangladesh, India, and Nepal combined while emitting less than half the PM emissions. The potential for energy saving and emissions reduction in South Asia is huge.
The World Bank is already involved in the brick sector in South Asia through the following activities:
- The innovative environmental project in Bangladesh, Clean Air and Sustainable Environment , aims at improving the urban air quality of Dhaka by reducing emissions from the brick making  and transport sectors.
- The Hoffman Hybrid Kilns Carbon Finance Project  includes 18 kilns in Bangladesh. By improving energy efficiency of the kilns and introduction of internal fuel use (mixing the clay with ground coal for making green bricks), each of the kilns produces about $75,000 in carbon credits per year.
- In India, the Bank has successfully helped leverage carbon benefits to the Fal-G brick  factories which use mainly fly ash and gypsum to produce compressed bricks . In this technology, alternative raw materials are used to replace clay. The bricks are compressed instead of fired, so no coal is used.
More needs to be done. The World Bank study Introducing Energy-efficient Clean Technologies in the Brick Sector of Bangladesh  estimates that producing one brick today in Bangladesh emits about 2.5 grams of PM and 500 grams of CO2 and creates health damage 2.1 taka (3 cents) per brick. Transforming that industry will lead to significant reduction of premature death and health problems; it will reduce energy dependency and contribute to less warming. The current vibrant momentum of mitigating SLCPs in the global climate change arena is a good opportunity to scale up our effort in the brick sector and black carbon emissions.