Earth began the transition toward a new glacial period 2,000 years ago, but human-driven global warming stopped this process in 1960. Research led by the University of Columbia, published October 22, 2026, in the journal Science, identifies the Barnes Ice Cap in Canada as the indicator of this interrupted shift.
Barnes Ice Cap Tracks Climate History
The Barnes Ice Cap, located on Baffin Island, Canada, acts as a geological time capsule. As the ice expanded, it buried mosses and dwarf shrubs that grew during warmer intervals. Researchers from the University of Columbia and other institutions used radiocarbon dating on these plant remains to map the historical extent of the ice.
This ice mass is the final remnant of the Laurentide Ice Sheet. That sheet once covered much of North America and reached thicknesses of more than three kilometers. Analysis shows the cap reached a minimum size 3,000 years ago. It began renewed growth 2,000 years ago, coinciding with orbital changes that favored cooler Northern Hemisphere summers.
Has global warming stopped/halted the next ice age? Columbia U: "Two thousand years ago, the Arctic remnants of a once-vast ice sheet started to grow again. It was the beginning of a new glacial period, more conversationally known as the next ice age—but by the 1960s, summer… pic.twitter.com/9LcqtEzRQZ
Human Activity Reverses Glacial Growth
For nearly two millennia, the ice cap grew because summer temperatures stayed low enough to prevent total melting of winter snow. This trend reversed in 1960. Rising atmospheric greenhouse gas concentrations increased summer temperatures, causing the ice cap to lose more mass annually than it could recover through winter snowfall.
It was starting, everything was normal, the next glaciation was about to occur and, however, it stopped. It is a very powerful example of how we have shaken the system.
Young, Researcher
Future Melting of Ice Reserves
Models indicate the Barnes Ice Cap will likely melt entirely within the next few centuries. This loss would eliminate the natural seed from which the Laurentide ice sheet had historically regenerated. Scientists suggest a new glacial period is not imminent on a human timescale. Even if human-caused warming were to cease, Earth remains in a long-term Cenozoic ice age that began 34 million years ago.
| Milestone | Approximate Date |
|---|---|
| End of last major glacial period | 11,700 years ago |
| Barnes Ice Cap minimum extent | 3,000 years ago |
| Start of renewed glacial growth | 2,000 years ago |
| Shift to ice cap recession | 1960 |