Humans Have Accidentally Stalled the Next Ice Age — But This Is Not Good News
A new study published in *Science* reshapes our understanding of Earth’s climate dynamics.
For millions of years, Earth has cycled between glacial and interglacial periods. Fluctuations between cold and warm phases are deeply embedded in the planet’s geological rhythm, driven by variations in Earth’s orbital configuration.
Unexpectedly, the next ice age—due to begin roughly two thousand years ago—has been abruptly halted by human emissions of fossil fuel-derived greenhouse gases.
The story begins on Baffin Island in Canada.
Here lies the last remnant of the Laurentide Ice Sheet: the Barnes Ice Cap.
Twenty thousand years ago, this massive ice sheet once extended across much of North America, with ice thickness exceeding 3,000 meters at its peak.
After the last glacial period ended, nearly all of the ice melted away, leaving only this ice cap—roughly the size of Delaware—as a vestige of the former giant.
Scientists have found that around 3,600 years ago, the ice cap reached its smallest extent in recorded history. Subsequent natural cooling triggered a re-expansion of the ice about 2,000 years ago—an event that marked the onset of the next glaciation cycle.
Many may wonder: how can scientists determine that an ice sheet is growing without thermometers from ancient times?
The key lies in the fact that the Barnes Ice Cap is frozen directly to bedrock and does not flow. As it advances, it does not scour or displace vegetation beneath it; instead, it buries mosses in place, preserving them intact.
Researchers extracted ancient mosses preserved beneath the ice margin and used radiocarbon dating to determine precisely when the ice covered and killed these plants. By analyzing rare isotopes in underlying rock, they also reconstructed the timing of burial, enabling a detailed reconstruction of the ice cap’s advance and retreat.
Under natural conditions, the ice cap would have expanded gradually over thousands of years, eventually evolving into a full-scale glacial period.
The turning point occurred in the 1960s.
Rising Arctic summer temperatures—driven by anthropogenic greenhouse gas emissions—accelerated melting beyond snow accumulation rates.
The nascent expansion of the ice cap reversed course and began rapid retreat.
Nicholas Young, a geochemist at Columbia University and lead author of the study, observed: “Everything was proceeding according to natural laws. The next ice age was imminent—then it stopped dead in its tracks. This demonstrates humanity’s capacity to disrupt Earth’s entire climatic system.”
⚠️ Do not interpret this as a silver lining: global warming has spared us from an ice age—what a blessing!
Scientists repeatedly emphasize that there is nothing to celebrate.
An ice age unfolds over tens of thousands of years. Even under natural conditions, it would take millennia for ice sheets to grow large enough to significantly affect human life.
We are not “saved”—we have violently disrupted a planetary climate rhythm that has governed Earth for millions of years.
The research suggests that human-driven greenhouse gas emissions may delay future ice ages indefinitely.
This study also resolves a long-standing internet meme: in the 1970s, some media outlets speculated that Earth might be entering a new ice age—a claim frequently cited by climate skeptics to discredit scientific consensus.
According to this new research, those early warnings were not baseless. The onset of glaciation had indeed begun—but was extinguished in its infancy by human-induced warming.
Of course, scholarly debate persists.
Some experts question whether the re-expansion of a single ice cap can be equated with the formal start of a new ice age.
Climate models suggest that even without human interference, a major glacial phase might still be tens of thousands of years away.
Further validation requires additional glacial records from across the globe.
Yet one fact remains incontrovertible: human emissions of greenhouse gases have already fundamentally altered the fate of Arctic ice caps.
We are no longer merely passive recipients of climate change—we have become a decisive force shaping Earth’s future.
Original: toutiao.com/article/1880429215575050/
Disclaimer: The views expressed in this article are those of the author alone.