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Two Thousand Years Ago, a New Ice Age Began—but Human-Caused Climate Change Recently Reversed It, According to New Research t.co/LgVzOTUqcs

Scientists have found that the ice cap began to expand around 2,000 years ago—a sign of a new ice age—but it started shrinking in the 1960s

At its peak around 20,000 years ago, it covered almost 30 percent of the continent, extending from above the Arctic Circle to what is now Illinois. The ice was more than two miles thick in some spots.

Over the past 2.6 million years, Earth has been cycling between times with large ice sheets, called glacial periods or colloquially, ice ages, and times without them, or interglacial periods.

The last glacial period ended around 11,700 years ago, and we are now in an interglacial period named the Holocene.

#GROK Smithsonian summary of a October 22, 2026 Science study by Nicolás Young and colleagues at Columbia University showing the Barnes Ice Cap on Baffin Island began expanding around 2,000 years ago after reaching minimum size 3,600 years ago.

#GROK The study interprets this reversal as human greenhouse gas emissions interrupting the onset of the next glacial period, highlighting how anthropogenic warming has altered natural Milankovitch-driven climate cycles observed over the past 2.6 million years.

#GROK A full glacial period involves major expansion of ice sheets over high- and mid-latitude landmasses (as the Laurentide once did across much of North America), lower global temperatures, altered precipitation patterns, and substantially lower sea levels

By Delaying Glaciations have we already messed up Earth's cycle.

This isn’t the first time researchers have speculated about the start of a modern ice age. Some climate scientists suggested in the 1970s that the world was on the verge of a new ice age.

“Humans are now geologic agents capable of thwarting millions of years of natural glacial cycles and offsetting Earth’s climate for hundreds of thousands of years to come.”

#GROK Even under strong emissions reductions that limit total cumulative carbon, the next realistic window for glacial inception is generally projected tens of thousands of years into the future