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According to the Environmental Protection Agency (EPA), which one of the following is the largest source of sulphur dioxide emissions ?
Explanation
The largest sources of SO2 emissions are from fossil fuel combustion at power plants and other industrial facilities.[5] This is clearly stated by the EPA across multiple references. In contrast, locomotives, ships and other vehicles and heavy equipment that burn fuel with a high sulfur content are classified as smaller sources of SO2 emissions.[2] Additionally, over 97% of the man-made sources are stationary, except for transportation sources (which include motor vehicles, vessels, and railroads).[7] This confirms that power plants, being major stationary sources using fossil fuels, are the largest contributors to sulfur dioxide emissions. Therefore, option D - Power plants using fossil fuels - is the correct answer according to the EPA.
Sources- [1] https://www.epa.gov/so2-pollution/sulfur-dioxide-basics
- [2] https://www.epa.gov/so2-pollution/sulfur-dioxide-basics
- [3] https://documents1.worldbank.org/curated/en/099032625132535486/pdf/P502230-d16d0858-2e18-41df-a7a6-f1188121ac83.pdf
- [4] https://www.epa.gov/so2-pollution/sulfur-dioxide-basics
- [5] https://documents1.worldbank.org/curated/en/099032625132535486/pdf/P502230-d16d0858-2e18-41df-a7a6-f1188121ac83.pdf
- [6] https://documents1.worldbank.org/curated/en/813211468331794803/pdf/multi0page.pdf
- [7] https://documents1.worldbank.org/curated/en/813211468331794803/pdf/multi0page.pdf
PROVENANCE & STUDY PATTERN
Guest previewThis is a 'Sitter' disguised as a 'Bouncer'. The tag 'According to EPA' is an intimidation tactic to make you think you missed a specific report. In reality, the answer relies on the most fundamental static fact of Environmental Science: Coal-fired power plants are the primary global source of SO2. Trust your basic NCERT/Shankar knowledge over the fear of missing a specific report.
This question can be broken into the following sub-statements. Tap a statement sentence to jump into its detailed analysis.
Web source
Presence: 5/5
"The largest sources of SO2 emissions are from fossil fuel combustion at power plants and other industrial facilities. Smaller sources of SO2 emissions include: ... locomotives, ships and other vehicles and heavy equipment that burn fuel with a high sulfur content."
Why this source?
- This EPA page explicitly states the largest SO2 sources are fossil fuel combustion at power plants and other industrial facilities.
- It then lists locomotives among 'smaller sources', showing locomotives are not the largest source per the EPA.
Web source
Presence: 4/5
"utilize coal and oils as fuel, are the leading sources of sulfur dioxide emissions. Except for transportation sources (which include motor vehicles, vessels, and railroads), over 97% of the man-made sources are stationary."
Why this source?
- States that sources which utilize coal and oil are the leading sources of sulfur dioxide emissions (i.e., stationary power/industrial sources).
- Notes transportation (including railroads) is a small fraction and that over 97% of man-made sources are stationary, implying locomotives are not the largest source.
- This EPA page explicitly states the largest SO2 sources are fossil fuel combustion at power plants and other industrial facilities.
- It then lists locomotives among 'smaller sources', showing locomotives are not the largest source per the EPA.
- States that sources which utilize coal and oil are the leading sources of sulfur dioxide emissions (i.e., stationary power/industrial sources).
- Notes transportation (including railroads) is a small fraction and that over 97% of man-made sources are stationary, implying locomotives are not the largest source.
Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 6: Environmental Degradation and Management > Acidification > p. 8
Strength: 5/5
âmotor vehicles inject large amounts of these chemicals into the atmosphere. In the atmosphere, the chemicals combine with water to form sulphuric acid and nitric acid. Tese droplets may be transported at great distances by wind before they precipitate to the ground (Fig. 6.1). Te main gases involved in the production of acid rains are nitrogen oxidesâsulphur dioxide (SO2), nitrogen dioxide (NO2) and nitrous oxide (NO). Te major sources of these gases is due to burning of fossil fuel and industrial processes. Acid rain is a phrase that applies to a process that results in deposition of acid on the surface of the Earth.â
Why relevant
States that sulphur dioxide (SO2) is one of the main gases producing acid rain and that the major sources are burning of fossil fuel and industrial processes.
How to extend
A student could use this general rule plus sector-level SO2 data (e.g., power plants vs. transportation) to judge whether locomotives (a transportation subâsector) are likely the largest source.
Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 17: Climate Change > The main sources > p. 256
Strength: 4/5
â⢠i. The combustion of fossil fuels to generate electricity.
⢠ii. The combustion of fossil fuels such as gasoline and diesel used for transportation.
⢠iii. Many industrial processes emit CO
e through fossil fuel combustion.
⢠iv. Several processes also produce CO
e emissions through chemical reactions that do not involve combustion, for example, the production and consumption of mineral products such as cement, the production of metals such as iron and steel, and the production of chemicals, etc.â
Why relevant
Lists combustion of fossil fuels for electricity and for transportation as main sources of emissions, implying transportation is a contributor but separate from electricity/industry.
How to extend
Compare relative emissions of the electricity sector (thermal power) and the transportation sector to see if the transport subsector 'locomotives' could dominate national SO2 emissions.
Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 6: Geomorphic Movements > Anthropogenic Solution Weathering > p. 91
Strength: 4/5
â⢠Rainfall is naturally acidic â pH of ~5.6 (CO2 dissolves in the rainwater producing weak carbonic acid). ⢠Sulphur dioxide, SO2, comes from volcanic eruptions or fossil fuels. The conversion of metallic ores to pure metals often results in the formation of sulphur dioxide.â
Why relevant
Specifies SO2 originates from volcanic eruptions or fossil fuels and notes metal production can form SO2, indicating multiple large nonâtransport sources.
How to extend
Use this to suspect that industrial processes and power generation (fossil fuel combustion) are important SO2 sources that may exceed locomotive emissions.
Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 6: Environmental Degradation and Management > Measures to Check Efects of Acidic Precipitation > p. 10
Strength: 4/5
âBoth in the developed and developing countries various remedial measures have been taken to reduce the adverse afect of acidic precipitation. Some of the remedial steps are: ⢠(i) Curtailing the emission of harmful gases and substances from the thermal and other chemical plants.⢠(ii) Compelling the industries to use better quality of coal which has low emission level of sulphur and other harmful substances.⢠(iii) Using alternate technologies for efcient use of fossil fuels.⢠(iv) Implementation of the environmental pollution laws more efectively.⢠(v) Environmental Impact Assessment on plants, animals, humanity and ecology before the establishment of any major or minor industry.⢠(vi) Public awareness about acidic rain and its impact on economy, society and ecology.â
Why relevant
Remedial measures emphasise curtailing emissions from thermal and other chemical plants and using lowâsulfur coal, implying thermal power and industry are priority SO2 sources.
How to extend
A student could infer that if policy targets thermal/industrial sources, those sectors likely contribute more SO2 than individual transport modes like locomotives.
Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 12: Transport, Communications and Trade > Main Features of Indian Railways > p. 12
Strength: 3/5
âPrior to Independence, the whole railways system was under steam traction. Since it had poor efficiency and caused great environmental pollution the diesel engines were introduced in 1950s. At present, Diesel Locomotive Works (DLW), Varanasi (UP), Chitranjan Locomotive Works (West Bengal), and Mihijam and Tat Engineering and Locomotive Works, Jamshedpur (Jharkhand), are producing diesel engines for railways. The diesel engines were also the cause of environmental pollution; therefore, in order to overcome the pollution problem and to cope with the growing pressure of traffic and goods, a decision was taken to switch over to electric traction all the important routes.â
Why relevant
Notes diesel locomotives were introduced and caused environmental pollution, later shifted to electric traction to reduce pollutionâshowing locomotives are a known source of emissions but not quantifying scale.
How to extend
Combine this with knowledge of fleet size/fuel use to estimate locomotive SO2 emissions and compare with larger stationary sources to assess relative rankings.
States that sulphur dioxide (SO2) is one of the main gases producing acid rain and that the major sources are burning of fossil fuel and industrial processes.
A student could use this general rule plus sector-level SO2 data (e.g., power plants vs. transportation) to judge whether locomotives (a transportation subâsector) are likely the largest source.
Lists combustion of fossil fuels for electricity and for transportation as main sources of emissions, implying transportation is a contributor but separate from electricity/industry.
Compare relative emissions of the electricity sector (thermal power) and the transportation sector to see if the transport subsector 'locomotives' could dominate national SO2 emissions.
Specifies SO2 originates from volcanic eruptions or fossil fuels and notes metal production can form SO2, indicating multiple large nonâtransport sources.
Use this to suspect that industrial processes and power generation (fossil fuel combustion) are important SO2 sources that may exceed locomotive emissions.
Remedial measures emphasise curtailing emissions from thermal and other chemical plants and using lowâsulfur coal, implying thermal power and industry are priority SO2 sources.
A student could infer that if policy targets thermal/industrial sources, those sectors likely contribute more SO2 than individual transport modes like locomotives.
Notes diesel locomotives were introduced and caused environmental pollution, later shifted to electric traction to reduce pollutionâshowing locomotives are a known source of emissions but not quantifying scale.
Combine this with knowledge of fleet size/fuel use to estimate locomotive SO2 emissions and compare with larger stationary sources to assess relative rankings.
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