Energy already contained by Earth is & has been used by mankind to meet needs that have grown larger with time. Much of the used energy is not being replaced fast enough.
There is sufficient new energy reaching Earth from star Sun continually & if fully utilised would be more than our future foreseen needs. When this was written in 2019 only a little of the continuing energy from Sun is generating electric power.
Our task then is to find ways of generating electric power sufficient to meet our present & future needs. Other devices such as reducing population etc. are not denied us.
On with the task.