Figure 14: Schematic of four factors which are believed to be primarily responsible for multi-decadal variations of the strength of the Atlantic thermohaline circulation. These are (A) the rate of Atlantic Ocean evaporation, (B) the rate of ice flow (eg., ice thickness) into the North Atlantic from the Arctic Ocean, (C) the rate of influx of warm saline water to Atlantic from the Indian Ocean, and (D) the rate of influx of relatively cold and fresh water from the South circumpolar currents. High values of processes (A) and (C) enhance the conveyor circulation, high values of processes (B) and (D) inhibit it.