Environment & Ecology
Context: Role of Industrial Aerosols in contributing to Global Cooling. A new study reveals that inactive volcanoes contributed 66 percent of sulphate emissions, known to cool the planet, in the preindustrial era.
About Aerosols:
- Aerosols are defined as a combination of liquid or solid particles suspended in a gaseous or liquid environment.
- In the atmosphere, these particles are mainly situated in the low layers of the atmosphere (< 1.5 km) since aerosol sources are located on the terrestrial surface.
- However, certain aerosols can still be found in the stratosphere, especially volcanic aerosols ejected into the high altitude layers.
- Source of aerosols
- Natural sources – sea salt generated from breaking waves, mineral dust blown from the surface by wind, and volcanoes.
- Anthropogenic aerosols – sulphate, nitrate, and carbonaceous aerosols, and are mainly from fossil fuel combustion sources.
Effects of aerosols:
- They affect the atmospheric chemical composition.
- They can reduce visibility.
- They have important impacts on air quality and human health (e.g. aerosols can cause damage to heart and lungs).
- They serve as nuclei for cloud droplets or ice crystals in ice clouds.
Source: DownToEarth
Previous Year Questions
Q.1) Among the following crops, which one is the most important anthropogenic source of both methane and nitrous oxide ?
- Cotton
- Rice
- Sugarcane
- Wheat
Q.2) Consider the following:
- Carbon monoxide
- Nitrogen oxide
- Ozone
- Sulphur dioxide
Excess of which of the above in the environment is/are cause(s) of acid rain? (2022)
- 1, 2 and 3
- 2 and 4 only
- 4 only
- 1, 3 and 4
