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Day 63 – Q 2. Why do some places on earth experience heavier air pollution than others? What role does climate play in this? Examine.

2. Why do some places on earth experience heavier air pollution than others? What role does climate play in this? Examine.  

पृथ्वी पर कुछ स्थान दूसरों की तुलना में भारी वायु प्रदूषण का अनुभव क्यों करते हैं? इसमें जलवायु की क्या भूमिका है? जांच करें


Air pollution may be defined as the presence of any solid, liquid or gaseous substance including noise and radioactive radiation in the atmosphere in such concentration that may be directly and/or indirectly injurious to humans or other living organisms, property or interferes with the normal environmental processes.


Air pollution is the mixing of unwanted and harmful substances such as chemicals, dust, auto emissions, suspended particles, gases among others in our atmosphere. It can be of two types; indoor and outdoor air pollution. It is a serious threat to the health of living beings and the different ecosystems found in our environment. According to WHO, it was the cause of death of approximately 7 million people around the world in 2014.

If we take the scenario of India,

  • High dependence on coal for power: share of coal in power generation in India continue to be around 80%. Power plants with poor technology and efficiency continue to be the major source of pollutants like CO and oxides of nitrogen and sulfur.
  • High levels of poverty
    • Dependence on fuelwood and kerosene for the purpose of lighting and cooking leads to high level of pollutants being released in rural and urban periphery
    • Over exploitation of commons like forests, grazing lands and mindless deforestation reduces the natural capacity to absorb pollutants
  • Poor governance: the issue of environment and pollution is still to get the policy priority it deserves. While agencies liked CPCB and SPCBs continue to be under-resourced and under-staffed, multiplicity of the state authorities at the ground level leads to poor coordination, lax enforcement of rules and lack of accountability as seen in Delhi. Absence of environmental governance continues to be a major challenge
  • Access to technology: India’s industrial landscape continues to be dominated by MSMEs which lack access to cleaner technologies. Agricultural waste burning is also the result of poor access to farm technologies
  • Unplanned urbanization: haphazard growth of urban areas has led to proliferation of slums and poor public transport has increased the burden of personal vehicles on the road. Landfills used for waste management also releases pollutants in the air. The rapid urbanization of the recent years if left unmanaged will further exacerbate the problem
  • Continentality: problem of pollution in the landlocked northern states gets exacerbated due to unfavourable winds and phenomenon of temperature inversion during winters

Most of the pollution of the air is caused because of the ignorance and negligence of humans but it is also true that some time the air can be polluted by natural causes.

The natural factors causing air pollution are:

  1. Forest fires
  2. Wind erosion
  3. Radioactivity released from decay of rocks
  4. Volcanic eruptions.

Forest fires produce giant masses of smoke which tend to drift over nearby villages and cities.

Occasional eruptions of volcanoes can eject huge amount of volcanic ash and lava onto the earth surface which introduces dust and smoke into the atmosphere thereby polluting the air.

Natural air pollution can also be caused when rocks decay over time and release gas such as radon which has adverse effects on our health.

Once pollutants are emitted into the air, the weather largely determines how well they disperse. Turbulence mixes pollutants into the surrounding air. For example, during a hot summer day, the air near the surface can be much warmer than the air above. Sometimes large volumes of this warm air will rise to great heights. This results in vigorous mixing.

Wind speed also contributes to how quickly pollutants are carried away from their original source. However, strong winds don’t always disperse the pollutants. They can transport pollutants to a larger area, such as the smoke from open burning or forest fires.

Sometimes the condition of the atmosphere is very still (stable) and there is very little mixing. This occurs when the air near the surface of the earth is cooler than the air above (a temperature inversion). This cooler air is heavier and will not want to move up to mix with the warmer air above. Any pollutants released near the surface will get trapped and build up in the cooler layer of air near the surface. Temperature inversions are very common in B.C., especially in mountain valleys, often forming during calm clear nights with light winds. They can even persist throughout the day during the winter.

Role of climate

Climate change can impact air quality and, conversely, air quality can impact climate change. 

Changes in climate can result in impacts to local air quality. Atmospheric warming associated with climate change has the potential to increase ground-level ozone in many regions, which may present challenges for compliance with the ozone standards in the future. The impact of climate change on other air pollutants, such as particulate matter, is less certain, but research is underway to address these uncertainties.


Given air pollution issues in the country, Government has launched National Clean Air Programme (NCAP) A time bound national level strategy for pan India implementation to tackle the increasing air pollution problem across the country in a comprehensive manner.

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