Thermohaline circulation is the global, density-driven ocean conveyor belt. It is propelled by differences in water temperature ("thermo") and salinity ("haline"). Cold, salty, and dense water sinks in polar regions, while warmer water rises near the equator, moving vast amounts of heat, oxygen, and nutrients worldwide. Climate Impact The thermohaline circulation is fundamentally responsible for redistributing solar heat across the planet. For example, it pulls warm surface water toward the North Atlantic, keeping the climate of Western Europe and Iceland significantly milder than other regions at the same latitude. It is also highly sensitive to global climate patterns. Rapid melting of polar ice sheets introduces massive amounts of fresh, less-dense water into the polar surface layer, which can disrupt the sinking process and potentially slow down the entire system.