Only logged in User can create notes
Only logged in User can create notes

General Studies 3 >> Enivornment & Ecology



1. Context

The Centre for Science and Environment (CSE), a Delhi-based organisation that focuses on environment-related research and advocacy, analysed data to indicate that much of the air pollution over the week (October 21 to 26, 2022) from within the City was caused by vehicular emissions.

2. Report findings

  • CSE's analysis of data from October 21 to 26 found that the local sources of pollution and vehicular emissions may have contributed around 51 per cent to the PM 2.5 levels in Delhi. Local Sources refer to the sources within the city.
  • Among these local sources, the next largest contribution was 13 per cent from residential sources and 11 per cent from industries.
  • Construction activities contributed around 7 per cent to PM 2.5, followed by 5 per cent each from the burning of waste and the energy sector. Road dust contributed around 4 per cent to PM2.5 levels.
  • The analysis also found that Delhi's local sources caused around 32.9 per cent of the pollution in the city.
  • The remaining share came from NCR districts (32.8 per cent), other districts (25.8 per cent) and biomass burning in the neighbouring states (9.5 per cent).
  • The analysis also used data from Google Maps to look at hourly traffic speed on 15 arterial roads in the city over the week.
  • A high level of congestion was noted on all of these roads with average speeds ranging from 27 kmph to 32 kmph, speed being used as an indicator for congestion. The traffic build-up was found to be highest on October 21 and 22.
With vehicles contributing to the nitrogen dioxide levels in the city, the hourly nitrogen dioxide level was also found to peak around the time that congestion was maximum on the roads.
The analysis noted: "Hourly NO2 levels during evenings could be high ranging between 73 µg/m³ to 86 µg/m³. This is the time when congestion is also high".
3. The usage of Data analysis
  • The analysis used data from the Decision Support System (DSS) developed by the Indian Institute of Tropical Meteorology (IITM).
  • The DSS provides hourly information on the sources of PM 2.5 in Delhi the contribution of different sectors to emissions and the contribution of emissions from Delhi and 19 districts in the neighbourhood.
  • The Model developed by IITM uses an emissions inventory prepared by The Energy and Resources Institute (TERI) in 2018, data from the Central Pollution Control Board monitoring stations and data from NASA satellites to generate forecasts on emission sources for five days.
Image source: WHO
4. The Way Forward
  • It asks for a "verifiable and measurable shift" to public transport by improving access, bus services, and integrating metro stations with other modes of transport, besides providing an extensive network of walking and cycling infrastructure to connect neighbourhoods.
  • Delhi needs congestion, pollution pricing, and other restraint measures to control traffic volume.
  • Targets set for the electrification of the new vehicle fleet should be accelerated and met.
For Prelims & Mains

For Prelims: Delhi air Pollution, climate change, Centre for Science and Environment, Indian Institute of Tropical Meteorology, The Energy and Resources Institute, NASA, Central Pollution Control Board, 
For Mains: 
1. Discuss the major reasons for the Air pollution in Delhi and Suggest remedial measures. (250 Words)
Previous year questions
For Prelims:

1. In the cities of our country, which among the following atmospheric gases are normally considered in calculating the value of Air Quality Index? ( UPSC 2016)

  1. Carbon dioxide
  2. Carbon monoxide
  3. Nitrogen dioxide
  4. Sulfur dioxide
  5. Methane

Select the correct answer using the code given below:

(a) 1, 2 and 3 only
(b) 2, 3 and 4 only
(c) 1, 4 and 5 only
(d) 1, 2, 3, 4 and 5

 Answer: (b)

2. Acid rain is caused by the pollution of the environment (UPSC 2013)

(a) Carbon Dioxide and Nitrogen

(b) Carbon Monoxide and Carbon Dioxide

(c) Ozone and Carbon Dioxide

(d) Nitrous Oxide and Sulphur Dioxide

 Answer: (d)

3. Biological Oxygen Demand (BOD) is a standard criterion for (UPSC 2017)

(a) Measuring oxygen level in blood

(b) Computing oxygen levels in forest ecosystems

(c) Pollution assay in aquatic ecosystem

(d) Assessing oxygen levels in high-altitude regions

Answer: (c)

For Mains:
1. Describe the key points of the revised Global Air Quality Guidelines (AQGs) recently released by the World Health Organisation (WHO). How are these different from its last update in 2005? What changes in India’s National Clean Air Programme are required to achieve revised standards? ( UPSC 2021)
Source: The Indian Express

Share to Social