Photo: Collected
Greenhouse gases in the atmosphere have risen from the burning of fossil fuels, and this has probably blocked the onset of Earth’s next ice age. That is the finding of a new study of an ice cap in the Canadian Arctic. Scientists have warned, however, that this is no reason for humanity to see it as good news; rather, it is evidence of the profound human influence on Earth’s natural systems.
The study, published in the journal ‘Science’, says that about 20,000 years ago the vast Laurentide Ice Sheet stretched from the Arctic Circle to the US state of Illinois, and in places it was nearly two miles thick. What survives of that ice sheet today is the Barnes Ice Cap on Baffin Island in Canada’s Nunavut territory, roughly the size of the US state of Delaware.
The researchers found that the Barnes Ice Cap shrank to its smallest size around 3,000 years ago. Later, as temperatures fell, the ice cap slowly began to grow again around 2,000 years ago. According to the researchers, this expansion can be seen as the early onset of a new glacial period, or ice age.
But around 1960 the picture changed dramatically. As summer temperatures rose with human-driven global warming, the ice cap began to shrink again.
Nicolas Young, one of the study’s authors and a geochemist at Columbia University’s Lamont-Doherty Earth Observatory, said a new ice age was beginning and everything was proceeding naturally, but then the process suddenly stopped. It is a powerful example of how big a change humans can bring to Earth’s natural systems, he said.
To understand how the ice cap advanced and retreated in the past, the scientists collected ancient moss buried beneath the ice and dated it. By analysing radioactive isotopes in the surrounding rocks, they tried to find out how long those rocks had been free of ice. Piecing this information together, they reconstructed the history of the ice cap’s expansion and retreat.
Scientists do, however, disagree over how to interpret the study. Meredith Kelly, a professor at Dartmouth College in the United States, praised the study’s methods but thinks a comparative analysis with glaciers in other regions is needed.
Andrey Ganopolski, a physicist at Germany’s Potsdam Institute for Climate Impact Research, is of the view that even without global warming, the next ice age might have taken another 50,000 years or so to begin. He therefore believes there is not enough evidence to call the expansion of a single ice cap the onset of a new ice age.
In the 1970s, the idea held by some scientists that the Earth was heading for a new ice age was discussed in the media. A Newsweek report headlined ‘The Cooling World’ also drew wide attention at the time. Climate change sceptics often cite the forecasts of that period as an example of scientists getting it wrong.
Young thinks the new study offers a chance to look at that debate afresh. But he warned that it would be wrong to conclude that global warming has saved humanity from the danger of an ice age, since ice age changes unfold over thousands of years. Rather, the study brings to light just how much human activity has altered Earth’s climate system. Scientists fear that because of greenhouse gases, the prospect of a new ice age could also be pushed back for a long time in the future.
Background
According to a Smithsonian Magazine report, the study was published in ‘Science’ on 22 October. It says the Barnes Ice Cap reached its smallest size about 3,600 years ago; sources differ on when the ice cap was at its smallest.
By the numbers
A Gizmodo report notes that climate models suggest the Barnes Ice Cap could disappear completely within the next 300 years.
At a glance
Study co-author Gifford Miller works at the Institute of Arctic and Alpine Research at the University of Colorado in the United States; according to a 22 October release from the university, the first studies of the Barnes Ice Cap in the 1950s and 1960s found the glacier to be roughly stable.
Sources
Original report: Ajker Patrika
Background sources: Smithsonian Magazine, October 2026; Gizmodo, October 2026; University of Colorado Boulder (INSTAAR), 22 October 2026
