Is it possible for us to greatly improve energy efficiency and shift to a variety of renewable energy resources before we do even more serious harm to our own life-support system and to many of the world’s other species? Is it necessary?

Is it possible for us to greatly improve energy efficiency and shift to a variety of renewable energy resources before we do even more serious harm to our own life-support system and to many of the world’s other species? Is it necessary? How could it be accomplished? Explain.