Why plant a tree?
In the last few hundred years, humans developed rapidly and adopted new ways of living. Building high-rises, quicker means of transportation and appliances and so on have helped us reach of goal of being faster, longer, stronger and the like but we overlooked the price which we were paying. We didn't understand that we were highly contributing towards destruction too, as we never thought of giving back resources we took from mother nature.
This irresponsible attitude of just consuming the resources without ever trying to replenish them, contributed to destruction like extreme weather and a lack in natural resources. This destruction has certainly surpassed all other benefits of our partial development. The effect of all our irresponsible attitude, whether it's increased number of flood, drought or any other calamity happening around the world are the results of our irresponsible contribution towards destruction.
We should plant trees because it's time for us to act responsibly.