As Arctic ice melts faster than anticipated, more freshwater enters the oceans. How would this affect thermohaline circulation? A) Reverse the circulation direction B) Speed up the circulation C) Slow down the circulation

The injection of large amounts of freshwater into the oceans from the melting Arctic ice would likely C) Slow down the thermohaline circulation.

Thermohaline circulation, often referred to as the "global conveyor belt," is a system of ocean currents that are driven by differences in water density. The density of seawater is affected by temperature (thermo-) and salinity (-haline). In the polar regions, especially in the North Atlantic, the ocean water gets very cold and becomes saltier due to sea ice formation, which leaves the salt behind in the remaining water. As a result, this water is denser and sinks, creating a driving force for deep water currents.

When additional freshwater from melting ice enters the oceans, it dilutes the seawater, decreasing its salinity. Because saltier water is denser than less salty water, the addition of freshwater reduces the overall density of the ocean water. Consequently, this makes it less likely to sink, which is a critical component of the thermohaline circulation. With reduced sinking, the 'engine' of the thermohaline circulation weakens, which in turn can slow down the entire circulation system.