The seven trumpets all have in common that the judgments that arise from them affect a third part. This means that they leave two thirds unaffected.
These are not natural catastrophes. To call them natural catastrophes implies they just happen as a result of various forces and influences of a physical nature in the world. No, in these pictures, God has brought these things about. He orchestrates or permits them. He unleashes them upon the world as a warning of judgement to come. You say, ‘This is very severe’, but when you think about it, it would be an awful thing if God never warned the world, if there was never any punishment of mankind now. If everything went on with no hardship, no catastrophes, no volcanic eruptions, no tsunamis, no problems; if people had never ever experienced anything outside their control, then when the final judgement came all society would have some right to rise up and say to God, ‘You never warned us.’ It is the kindness of God that gives these token warnings, these partial judgements. And yet mankind hardens himself, and he is so proud, and he explains all in terms of natural causes, so that he closes his mind to anything being of divine orchestration or origin. That is the pride of man.
With what great foresight the Lord does what he does! He knew from the start that those judgments on Egypt would model what he would later do to the entire world.