Human Activity Stopped Potential Ice Age, Scientists Say

A shrinking ice cap in Arctic Canada suggests human activity may have stopped the planet's next ice age, according to new research. The Barnes Ice Cap, located on Baffin Island, began re-expanding roughly 2,000 years ago, marking the start of a potential new ice age.

However, human-driven climate change caused the ice cap to shrink starting in the 1960s. Scientists believe the rise in greenhouse gas emissions disrupted the natural process of ice growth, preventing the full development of a new ice age.

The study, published in the journal Science, analyzed long-dead mosses and radioactive isotopes in rocks to reconstruct the ice cap's history. These methods revealed that the ice sheet reached its smallest size around 3,000 years ago and began regrowing in response to cooler temperatures.

Researchers argue that the regrowth of the Laurentide Ice Sheet counts as the start of an ice age, even though it never reached its full potential. They suggest that the timing of this regrowth coincides with the significant increase in greenhouse gas emissions from human activities.

Other scientists, however, caution that the growth of the Barnes Ice Cap alone does not confirm the start of a new ice age. Some studies suggest the next ice age would not occur for at least 50,000 years, even without human-induced climate change.

The findings also throw new light on a controversial period in the 1970s when some scientists suggested the world might be entering a new ice age. While this idea was later dismissed, the new research suggests those scientists may have been correct in their initial assessment.