In its simplest form, we are harvesting the finite, underground, carbon- based resources (coal, oil and natural gas), converting them into usable energy, and leaving excess CO2 in the atmosphere and fewer resources for future generations.. Here is a hypothesis which I am contemplating. If over time we converted much of our industrial agriculture into edible food forests, the trees would absorb excess CO2, provide food for us, and leave an annual crop of branches and dead limbs (i.e. stored carbon).