A hidden climate shift may have sparked epic Pacific voyages 1,000 years ago

Around 1,000 years ago, a major climate shift reshaped rainfall across the South Pacific, making western islands like Samoa and Tonga drier while eastern islands such as Tahiti became increasingly wet. New evidence from plant waxes preserved in island sediments shows this change coincided with the final major wave of Polynesian expansion eastward. As freshwater became scarcer in the west and more abundant in the east, people may have been pushed to migrate, effectively “chasing the rain” across vast stretches of ocean.