This site has argued that global warming is happening. Man-made carbon emissions have warmed the planet to the degree where it has triggered the start of numerous natural global warming self-reinforcing feedback loops. Those who think the Paris climate accord would help stop global warming are wrong. There is already enough carbon in the atmosphere so that even if man completely stopped all emissions tomorrow, the global average temperatures will still rise a further 5 degrees centigrade. Once this becomes the new consensus, the world will stop focusing on carbon emission reductions, and will instead focus on carbon removal from the atmosphere.
There have already been limited geoengineering experiments which attempted to remove carbon from the atmosphere. The easiest and most tested method so far has been the dumping of iron dust into the ocean. The iron serves as nutrients for algae, so when iron dust is dumped into the ocean, massive algae blooms occur. The algae removes carbon from the atmosphere. When the algae dies, it serves as a carbon sink for a few years as the dead algae sinks to the bottom of the sea.
In Revelation 8:8-9, it says:
And the second angel sounded, and as it were a great mountain burning with fire was cast into the sea: and the third part of the sea became blood;
9And the third part of the creatures which were in the sea, and had life, died; and the third part of the ships were destroyed.
There is a possibility that it will be man himself whose actions will trigger the sea turning to blood. When global warming worsens to the point where one third of the world’s trees burn (Revelation 8:7 ), man will panic. Perhaps it will be the UN that calls for action to reduce the carbon in the atmosphere. The easiest thing to do will be to dump massive amounts of iron dust into the ocean, on a global basis. An algae bloom that covers a third of the world’s ocean will occur, as anticipated by the experimenters. However, because the temperature of the ocean water will rise in conjunction with the rising atmospheric temperatures, the massive algae bloom will turn into a massive red tide (as warmer ocean temperatures is conducive to blooms of red tide algae) — turning the ocean blood red, killing off all marine life trapped in the red tide.
It is possible for God to use His omnipotence to literally turn the ocean water into blood, but it is also possible that God will allow man to do this for Him, and in the process, bring about the manifestation of the prophecy.
The signs of Revelation surround us.