3 trillion divided by 15 billion = never run out as trees grow back.
Oh my gosh, “trees grow back?” I never knew that. I was taught in the guvmint skools that trees were too valuable to be used because once they were cut down, the land was paved over or let to erode into great canyons. Gee, does the guvmint know that trees grow back? Somebody ought to tell them and they can spend a billion dollar study to see if it is actually true.