Answer:
Carbon dioxide (CO₂) is an important green house gas. A small increase in the concentration of this gas can lead to the global rise in the surface temperature. Over the last 100 years, this gas has increased significantly. One of the main cause behind this the anthropogenic activities.
After the setup of the industrial revolution, there has been a large increase in this CO₂ concentration, as there are numerous large factories and indutries that releases this harmful gases. In addition to this, the burning up of fossil fuel also is responsible for the emission of large amount of carbon into the atmosphere.
Deforestation also is another cause, because trees are no longer there in vast quantities which takes up a large number of atmospheric carbon and in return liberates plenty of oxygen.
Thus, the activities done by man over the last century has led to the increase in the concentration of CO₂ into the atmosphere.
