When carbon dioxide is increased in the atmosphere, it leads to ________.
- A.Global warming
- B.Air pressure
- C.Conservation
- D.Rains
Show answer
Correct answer: A. Global warming
Explanation
The correct answer is A, global warming. Carbon dioxide is a greenhouse gas: it lets in the short wave radiation of the sun but absorbs a part of the long wave infrared radiation that the warmed earth sends back, and radiates it downwards again. As its concentration rises with the burning of coal, oil and gas and with deforestation, more heat is held in the lower atmosphere and the average surface temperature of the earth rises. That rise is global warming, and it is the central driver of present day climate change.
Option B, air pressure, depends on temperature, altitude and the mass of air above a place, not on the share of a trace gas. Option C, conservation, is the protection and wise use of resources and is a human activity, not a consequence. Option D, rains, may change in pattern as the climate warms, but that is an indirect effect rather than the direct result asked for here.