Humans Thrived in Harsh Ice Age Conditions 25,000 Years Ago: New Research

Ancient humans demonstrated remarkable endurance and adaptability by surviving on the Tibetan Plateau—the highest plateau on Earth—during the coldest era of the past 2.5 million years.

The last glacial maximum, occurring between 26,500 and 19,000 years ago, marked the most extreme phase of the Late Pleistocene ice age. During this period, extensive ice sheets and polar caps blanketed vast regions of the Earth, with global temperatures dropping approximately 4 to 5 degrees Celsius below current averages, according to the New Scientist.

"The Tibetan Plateau was previously thought to be uninhabitable during the last glacial maximum," states Wenli Li of the University of Chinese Academy of Sciences in Beijing. "Extreme cold, sparse vegetation and low oxygen levels at high altitudes made survival incredibly difficult."

Although previous evidence suggested that humans occupied the plateau before and after this icy epoch, no direct proof of habitation during this period had been discovered, until now. In 2019, LI and her team unearthed a site 3,800 meters above sea level in the Yarlung TsagpoRiver valley on the southern Tibetan Plateau, The excavation revealed numerous artifacts, indicating human presence during this challenging time.

Researchers discovered 427 artifacts, including stone tools and the first-ever ochre fragments–red-coloured minerals used in ancient art—found in Tibet.

Radiocarbon dating of ancient bones and charcoal from the site identified three distinct periods of human occupation between 29,200 and 23,100 years ago. Notably, two of these phases, around 25,000 and 23,000 years ago, overlapped with the last glacial maximum.

"No archaeological site had previously been dated to this period," remarks Feng He of the University of Wisconsin-Madison, who was not part of the research. "This discovery reinforces the idea that early humans were highly resilient and adaptable to extreme conditions."

To gain further insight into the environment during these occupations, scientists analyzed nearby stalagmites and lake sediment cores. These geological samples provide valuable climate data through their chemical composition. Findings indicate that the river valley retained more moisture than expected for the otherwise arid ice age conditions in Tibet, allowing cold-resistant plants and herbivorous wildlife to thrive.

"The valley likely provided essential resources—water, vegetation, and game needed for survival," explains Li.

Stone tools discovered at the site bear a resemblance to artifacts from older sites deeper within the plateau's interior. Li suggests that as conditions grew colder and drier, people may have migrated into the river valley in search of more hospitable environments.

Earlier studies had hypothesized that river valleys on the southern Tibetan Plateau served as refuges for early inhabitants escaping the worsening glacial conditions, says He. "It's satisfying to see that this discovery supports that hypothesis."

Looking ahead, Li and her team aim to delve deeper into how climate shifts during the last glacial maximum influenced human settlement and movement in the region. The site, now named Pengbuwuqing after a nearby hill, holds great potential for unraveling more secrets about human survival in extreme environments.