Answer:
Option (4)
Explanation:
Carbon forms the basin element for the existence of life. It is present in the atmosphere in the form of CO₂, which is one of the major green house gas. It plays an important role in the carbon cycle.
The increase in the concentration of carbon in the atmosphere can lead to the global rise in the temperature. It can lead to global warming. The amount of carbon in the atmosphere has been rising continuously, right after the industrial revolution.
The carbon is mainly emitted from the heavy industries and factories, vehicles, burning up of fossil fuels. It also increased due to the increasing absorption of solar radiation.
This emission of carbon if not controlled by the humans, then the concentration of carbon in the atmosphere will abruptly increase after some decades.
Thus, the correct answer is option (4).
