I'd say that the natural is what YHVH created by speaking it into existence.
Psa 33:6-9 WEB 6 By Yahweh’s word, the heavens were made: all their army by the breath of his mouth. 7 He gathers the waters of the sea together as a heap. He lays up the deeps in storehouses. 8 Let all the earth fear Yahweh. Let all the inhabitants of the world stand in awe of him. 9 For he spoke, and it was done. He commanded, and it stood firm.
We read in Romans 5 that through the sin of Adam, death entered the world.
Rom 5:12 WEB Therefore as sin entered into the world through one man, and death through sin; so death passed to all men, because all sinned.
Death is the result of sin.
Something else that strikes me....
All creation groans because of sin.
Rom 8:16-28 WEB 16 The Spirit himself testifies with our spirit that we are children of God; 17 and if children, then heirs: heirs of God and joint heirs with Christ, if indeed we suffer with him, that we may also be glorified with him. 18 For I consider that the sufferings of this present time are not worthy to be compared with the glory which will be revealed toward us. 19 For the creation waits with eager expectation for the children of God to be revealed. 20 For the creation was subjected to vanity, not of its own will, but because of him who subjected it, in hope 21 that the creation itself also will be delivered from the bondage of decay into the liberty of the glory of the children of God. 22 For we know that the whole creation groans and travails in pain together until now. 23 Not only so, but ourselves also, who have the first fruits of the Spirit, even we ourselves groan within ourselves, waiting for adoption, the redemption of our body. 24 For we were saved in hope, but hope that is seen is not hope. For who hopes for that which he sees? 25 But if we hope for that which we don’t see, we wait for it with patience. 26 In the same way, the Spirit also helps our weaknesses, for we don’t know how to pray as we ought. But the Spirit himself makes intercession for us with groanings which can’t be uttered. 27 He who searches the hearts knows what is on the Spirit’s mind, because he makes intercession for the saints according to God. 28 We know that all things work together for good for those who love God, for those who are called according to his purpose.