Did humans cancel the next ice age? Ancient moss reveals an ice cap growing for centuries and global warming may have reversed it, here's what scientists found

Long before anyone burned coal to power factories, an ice cap in Arctic Canada was slowly spreading across the ground. Plants growing in its path disappeared beneath the ice. Researchers studied the remains of those plants and used that as evidence to reconstruct the history of the Barnes Ice Cap on Baffin Island. They reached to a conclusion which was baffling everyone:the ice began growing again about 2,000 years ago, before human-driven warming reversed its expansion around 1960. The team interprets that reversal as the end of an emerging ice age. So did humans prevent an ice age from happening or is it just a theory?

What did researchers discover about the Barnes Ice Cap?

The clues were small plants, including mosses, preserved beneath the ice. The Barnes Ice Cap is frozen to the rock underneath. It does not slide across the landscape and scrape away evidence as many glaciers do.

Researchers dated the dead plants to determine when advancing ice covered them. Samples from different locations helped show how its edge moved over time.


The Barnes Ice Cap lies in Canada’s Nunavut territory. It is a surviving remnant of the Laurentide Ice Sheet, which once covered much of Canada and extended into the northern United States.

The new study, published in Science on October 22, reconstructed how the remaining ice changed over thousands of years. After reaching a small size several thousand years ago, the ice cap began expanding roughly 2000 years ago.

Around 1960, that growth stopped. Warmer summers caused it to lose more ice than it gained which pushed its edge backwards.

How can dead moss reveal the history of ice?

According to the report by CNN, researches had studies the Barnes Ice Cap. They found it is frozen even to the rock it stands on. So, it is different from other glaciers as does not slide across the landscape. It also plants to grow underneath it and this was the biggest clue for the scientists.

As the ice kept expanding, it covered those plants and killed them. Now, Scientists have found those remains of plants.

Researchers have dated the plants to establish when they died. Repeating that process at different locations helped the build the timeline about how ice moved towards the plants and where.

A team of researchers also examined rocks close to Barnes Ice Cap to get some chemical clues. This was done to determine how long the rocks have been there. Chemical traces appear on rocks when they have been exposed to cosmic rays for a long time.

Does growing Arctic ice mean an ice age had begun?

The study’s authors argue that renewed growth marked the first stage of another glaciation. A glaciation is a colder period when large ice sheets expand. People commonly call it an ice age.

Lead author Nicolás Young, a geochemist at Columbia University’s Lamont-Doherty Earth Observatory, argues that scientists need not wait for enormous ice sheets before recognising that beginning.

However, identifying local ice growth and declaring a new global glacial cycle are different conclusions.

Why do other scientists disagree?

The CNN report mentioned that while the evidences are there it is still not enough to establish that a new glacial cycle had begun. Andrey Ganopolski, a physicist at the Potsdam Institute for Climate Impact Research, was quoted in the report and said that the Barnes Ice Cap’s expansion alone does not establish that a new glacial cycle had started.

His earlier studies have suggested that even without suggested that, even if we remove the warming of Earth caused bu humans, the next glaciation would not begin for about 50,000 years which is still a long period.

Dartmouth earth scientist Meredith Kelly said it is important to compare glaciers at more places to have a better understanding of the changes and their impact.

Why isn’t stopping an ice age good news?

The study conducted by researchers does not prove, for now, that there was a wall of ice heading towards cities and human populations, so worrying about it was still far-fetched. However, Young explained that if it was happening, it would still have taken thousands of years to occur. So we can’t say that humans burned fossil fuels and prevented an ice age from happening.

On the contrary, it shows how warming is impacting our glaciers, plants and human life.