Question 81 from UPSC CSE 2024 - Current Affairs (Environm ent)

Question

According to the Environmental Protection Agency (EPA), which one of the following is the largest source of sulphur dioxide emissions?

IASCODEX · Accepted Answer

Correct Option: D. Power plants using fossil fuels

Strategy: Focus on the scale and nature of emissions --

Among the options, burning fossil fuels at power plants operates at much larger scales and intensity compared to transport sources like locomotives or ships, or processes like ore extraction. This aligns with EPA reports highlighting power plants as the highest contributors to atmospheric SO2 emissions. Industrial stationary sources typically outweigh mobile or process-related sources for such widespread pollutants.

Key Info: Sulphur dioxide (SO2) is a significant air pollutant mainly generated by the combustion of fossil fuels containing sulfur, primarily coal and oil.

According to the United States Environmental Protection Agency (EPA), fossil fuel-fired power plants are the largest anthropogenic (human-caused) source of SO2 emissions in the U.S. and globally. These large, stationary sources burn considerable quantities of high-sulfur fuels to produce electricity, resulting in massive SO2 release.

Other sources include industrial processes such as extraction and smelting of metals from sulfide ores, petroleum refineries, and mobile sources (locomotives, ships, heavy equipment). However, these contribute far less compared to the scale from power generation.

The EPA regulates SO2 under the Clean Air Act and sets National Ambient Air Quality Standards (NAAQS) to protect against health effects such as respiratory problems and environmental harm like acid rain. The EPA is an independent U.S. federal agency founded in 1970, tasked with enforcing environmental protection regulations, research, and education.

IASCODEX · Answer

Option A: Locomotives using fossil fuels

IASCODEX · Answer

Option B: Ships using fossil fuels

IASCODEX · Answer

Option C: Extraction of metals from ores