Correct Option
The correct option isCarbon Dioxide
Explanation
Global warming refers to the long-term rise in the average temperature of the Earth's climate system. This phenomenon is primarily driven by the Greenhouse Effect, where specific gases in the atmosphere trap heat radiating from Earth toward space. These gases are collectively known as Greenhouse Gases (GHGs).
Option Analysis
- Sulphur Dioxide Sulphur Dioxide ($SO_2$): Incorrect. Sulphur dioxide is a major air pollutant primarily released from the burning of fossil fuels containing sulphur. It is a precursor to acid rain and contributes to the formation of atmospheric aerosols, which typically have a cooling effect on the climate by reflecting sunlight, rather than causing warming.
- Carbon Monoxide Carbon Monoxide ($CO$): Incorrect. Carbon monoxide is a toxic gas produced by incomplete combustion. While it has a weak indirect effect on global warming by affecting the lifetime of methane and ozone, it is not considered a primary direct greenhouse gas.
- Carbon Dioxide Carbon Dioxide ($CO_2$): Correct. Carbon dioxide is the most significant long-lived greenhouse gas in Earth's atmosphere. It is released through natural processes (e.g., respiration, volcanic eruptions) and human activities (e.g., deforestation, burning fossil fuels). Due to its high concentration and long atmospheric residence time, it is responsible for the majority of the anthropogenic radiative forcing causing global warming.
- Nitrogen Dioxide Nitrogen Dioxide ($NO_2$): Incorrect. Nitrogen dioxide is a pollutant that contributes to the formation of photochemical smog and acid rain. While Nitrous Oxide ($N_2O$) is a potent greenhouse gas, Nitrogen Dioxide ($NO_2$) itself is not the primary driver of global warming.
Key Takeaway
Carbon Dioxide ($CO_2$) is the primary greenhouse gas responsible for anthropogenic global warming, contributing the largest share to the enhanced greenhouse effect due to its abundance and emissions from fossil fuel combustion.