BURSTNature, Published online: 21 October 2026; doi:10.1038/d41586-026-03285-8
A 450,000-year stalagmite record of rainfall in the Amazon Basin , combined with existing Asian records, shows that the global monsoon system has oscillated regularly, strengthening in one hemisphere while weakening in the other. However, during intervals of warmth and warming climate, monsoons in both hemispheres failed for millennia.