As anybody who has touched a dark colored car on a hot summer’s day can attest, dark substances like black carbon do not reflect light and instead emit heat to their surroundings. According to the United Nations Environment Program (UNEP), cutting back on "short-lived" climate pollutants like black carbon may reduce global warming expected by 2050 by as much as 0.5 degrees Celsius (32.9 degrees Fahrenheit).
The nice thing about addressing this problem is that the impact is immediate. Black carbon does not linger in the air for long; any improvement will be seen in a few weeks time. Curbing black carbon emissions will also help eliminate a major cause of Arctic ice melting. Black carbon, carried by winds, lessens ice reflectivity and increases melting, which affects the Earth’s ability to reflect sunlight back to space.
Poverty and lax enforcement of laws have caused poorly designed cook stoves, badly maintained engines, and cultural practices such as clearing of dry brush by burning to exacerbate the problem in poorer countries. Since black carbon is a product of incomplete combustion, it is actually easy to fix. Sometimes, all that is needed to reduce or eliminate emissions is an engine tune-up. In other cases, fully dilapidated engines that are still running on the road need to be replaced or rebuilt, and inefficient cook stoves replaced.
But all these changes take money, and often individuals and governments have neither the resources nor incentives to make them. For example, a predominant means of transportation for a poor man in the Philippines, the jeepney (a converted American jeep that can carry roughly 20 passengers), is often built using surplus and rebuilt parts. Jeepney operators have very little cost incentive to use a modern, clean-burning engine, as the profit margin for their business is extremely low. And anti-smog laws are often undermined by poor enforcement.