v.3 Then the second angel poured out his bowl on the sea, and it became blood as of a dead man; and every living creature in the sea died.
This “second judgment” is poured out upon the sea.
As a result, the oceans become blood, in turn killing every fish, mammal, and organism in every ocean in the world. This will not only contribute to famine, but considering the valuable food chain that the oceans supply, will undoubtedly have a devastating impact on the world’s economy as well.
v.4 Then the third angel poured out his bowl on the rivers and springs of water, and they became blood.
This “third judgment” is poured out upon the rivers and springs.
This causes all the fresh water both above and below ground to become blood; thereby eliminating the presence of all drinking water, and further reducing the availability of food generally provided by fresh water lakes and streams.
v.5-7 And I heard the angel of the waters saying: “You are righteous, O Lord, the One who is and who was and who is to be, because You have judged these things. For they have shed the blood of saints and prophets, and You have given them blood to drink. For it is their just due.” And I heard another from the altar saying, “Even so, Lord God Almighty, true and righteous are Your judgments.”
This is heaven’s reassurance that God’s judgments are purposeful and just.
Note how incessantly ready the angel is for them to finally occur and how genuinely righteous the angel acknowledges them to be; and who better, but an angel, could give testimony to such things. For angels know the whole story of man’s rebellion, and have remained astute witnesses to the bloodshed of God’s saints from the very beginning.
It’s unclear whether this “angel of the waters” is a specific angel whose duties might include charge over the waters, or the third angel whose bowl turned the waters to blood.
As for the answering cry made from the altar, it would seem that that came from the souls of the Tribulation martyrs John saw earlier at the altar crying out for God to avenge them (Rev.6:9-11).
v.8-9 Then the fourth angel poured out his bowl on the sun, and power was given to him to scorch men with fire. And men were scorched with great heat, and they blasphemed the name of God, who has power over these plagues; and they did not repent and give Him glory.
This “fourth judgment” is poured upon the sun.
This results in men being scorched so severely by fire and great heat that the prophet Malachi refers to it figuratively as an oven that will burn up the wicked like stubble.
“For behold, the day is coming, burning like an oven, and all the proud, yes, all who do wickedly will be stubble, and the day which is coming shall burn them up” (Mal.4:1)
The cause of this solar event is speculative. Some have suggested a super nova (a process at the end of a star’s life in which it becomes intensely brighter just before it burns out). Others see it as a dramatic depletion in the ozone layer resulting in extremely high levels of ultra violet rays.
Whatever its cause, the hearts of the people in these last days would have become so incurably wicked that even in their suffering, rather than repent, they only grow in their contempt for God (see also—2Tim.3:13).