In the six hundredth year of Noah’s life, in the second month, the seventeenth day of the month, the same day were all the fountains of the great deep broken up, and the windows of heaven were opened. And the rain was upon the earth forty days and forty nights.
(Genesis 7:11-12) KJV
After a period during which humanity experienced global warming, the Earth reached boiling Point: Noah’s flood.
The expansion of hell caused the waters of the great deep and heat up to boiling point, at which time the water and steam burst forth out of the fountains of the great deep.

Lower Noachian
After a period during which humanity experienced global warming, the Earth reached boiling Point: Noah’s flood.