Airplanes eject Black carbon,impact environment

Why in News?

According to a study by climate researchers from multiple institutions in the country, Aeroplanes may be ejecting significant amounts of black carbon (BC), which have an impact on Monsoon, quicken glacier melt, and deplete the ozone layer.

FACTS (For Prelims )

1.Chemically, black carbon (BC) is a component of fine particulate matter and consists of pure carbon in several linked forms. It is formed by the incomplete combustion of fossil fuels, biofuel, and biomass, and is emitted in both anthropogenic and naturally occurring soot.

2.Black carbon is estimated to have a 20-year Global Warming Potential (GWP).

3.Global Warming Potential-It is a relative measure of how much heat a greenhouse gas traps in the atmosphere. It compares the amount of heat trapped by a certain mass of the gas in question to the amount of heat trapped by a similar mass of carbon dioxide.

4.Indian Meteorological Department (IMD) has launched a System of Aerosol Monitoring and Research (SAMAR) to study the concentration of black carbon in the atmosphere due to air pollution and its impact on climate.

ANALYSIS (For Mains )

Though airborne, Black Carbon  is known to dissipate and settle down in a few months under the influence of rain and wind and is unlikely to travel upward of 4 km. However, a group of scientists say they now have evidence of such particles existing up to 18 km into the stratosphere and there are about 10,000 of them in every cubic centimetre.

Key features of the study-

1.It  shows that Black Carbon exist up to 18 km into the stratosphere, a stable region of the atmosphere.

2.Given the shape and location of these particles, researchers  believe that they could only be derived from emissions from aviation fuel.

3.As Black Carbon  particles absorb heat, they warm the surrounding air, become lighter and rise to greater heights by a process called self-lift and persist for a long time in the atmosphere.

Impact of Black Carbon-

1.Black carbon warms the Earth by absorbing sunlight and heating the atmosphere and by reducing albedo when deposited on snow and ice (direct effects) and indirectly by interaction with clouds.

2.IPCC’s report estimate that emissions from black carbon are the second-largest contributor to global warming after carbon dioxide emissions, and that reducing these emissions may be the fastest strategy for slowing climate change.

Controlling Black Carbon-Policy options

Many countries have existing national laws to regulate black carbon emissions, including laws that address particulate emissions. Some examples include:

1.banning or regulating slash-and-burn clearing of forests and savannas;

2.requiring shore-based power/electrification of ships at port, regulating idling at terminals, and mandating fuel standards for ships seeking to dock at port;

3.requiring regular vehicle emissions tests, retirement, or retrofitting  including penalties for failing to meet air quality emissions standards, and heightened penalties for on-the-road “super-emitting” vehicles;

4.banning or regulating the sale of certain fuels or requiring the use of cleaner fuels for certain uses;

5.limiting the use of chimneys and other forms of biomass burning in urban and non-urban areas;

6.requiring permits to operate industrial, power generating, and oil refining facilities and periodic permit renewal and/or modification of equipment; and

7.requiring filtering technology and high-temperature combustion (e.g. supercritical coal) for existing power generation plants, and regulating annual emissions from power generation plants.