I think the thermohaline circulation would still occur even if the earth rotated in the opposite direction. That is, seawater would still cool and sink to the bottom of the North Atlantic Ocean to form North Atlantic Deep Water. I think the ocean would continue to warm the air over the North Atlantic as deepwater sinks and that this warmed air would move eastward over northern Europe to moderate the climate there.

Ice would continue to form around Antarctica. This would still cause seawater to gain salt over the continental shelves of Antarctica, especially in the Weddell Sea and Ross Sea, to form Antarctic Bottom Water. This dense water would then flow downward from the continental shelves to the bottom of the Southern Ocean. I think the overall thermohaline circulation pattern would continue. Sincerely,