Final answer:
High-latitude oceans are becoming fresher as a result of global warming, which leads to increased ice melting and changes in precipitation patterns, thus diluting the ocean's saline waters.
Step-by-step explanation:
The high-latitude oceans have been becoming more fresh due to global warming. As global temperatures rise, glaciers and polar ice melt, introducing freshwater into the oceans. This influx of freshwater dilutes the saline ocean waters, particularly in the Arctic and Southern Oceans. Furthermore, global warming alters precipitation patterns and increases the volume of water from melting ice, which can lead to a greater influx of fresh water into these high-latitude oceans. Additionally, the warming of the ocean surface can stratify the water column, preventing the mixing of deeper saline waters with the fresher water at the surface, thus maintaining or enhancing the freshwater layer. Significant consequences of this process include changes in ocean circulation and possible impacts on marine life due to the altered salinity levels.