A phase of intense aridity about 4.2 ka BP is recorded across North Africa, the Middle East, the Red Sea, the Arabian Peninsula, the Indian subcontinent, and midcontinental North America. Glaciers throughout the mountain ranges of western Canada advanced about that time. Evidence has also been found in an Italian cave flowstone, the Kilimanjaro ice sheet, and in Andean glacier ice. The onset of the aridification in Mesopotamia in about 4100 BP also coincided with a cooling event in the North Atlantic, known as Bond event 3. However, evidence for the 4.2 kyr event in Northern Europe is ambiguous, which suggests that the origins and the effects of the event to be spatially complex.