Answer: the greenhouse effect, global warming
Step-by-step explanation:
The human activities produce greenhouse gases such as carbon dioxide, carbon monoxide, methane, nitrogen oxides and others. These gases when enter into the atmosphere because of their diatomic structure are capable of trapping the light energy from sun. The abundance of these gases in the air is making the global temperature warm, which is chiefly responsible for drought like conditions and melting of glaciers in some locations. The trapped sunlight cannot be reflected back to the space this phenomena is called as greenhouse effect and the phenomena of increase in global temperature is called as global warming.