If thermohaline circulation ceased, what might happen? nothing; it's in the ocean. a significant change would occur in the rock cycle. a significant change would occur in climates.

A significant change would occur in climates.

Explanation:

Thermohaline circulation is the circulation of the ocean currents throughout the world, if Thermohaline ceased from one day to the other, it would create significant changes in our climates, for example, many of this currents are used by animals to migrate, many of this currents also warm up or cool off certain regions of the ocean in order to regulate the temperature of the planet, so just with those two we would face severe problems, warmer summers and springs, and colder winters and autums, we could even face the dissappearing of spring and autumn.