Quantcast
Environmental News for a Healthier Planet and Life

Help Support EcoWatch

Researchers Discover Arctic Warmer Than Anytime in Last 44,000 Years

Climate
Researchers Discover Arctic Warmer Than Anytime in Last 44,000 Years

By Tim Radford

Good news for Arctic mosses, if not for any other Arctic creatures: little tundra plants that have been buried under the Canadian ice can feel the sunlight for the first time in at least 44,000 years.

The implication is that the Arctic is now, and has been for the last 100 years, warmer than at any time in the last 44,000 years and perhaps for the last 120,000 years.

Researchers have found that the Arctic is warmer now than it was in the early Holocene—the end of the last Ice Age—when the peak summer sunlight was roughly nine percent greater than present day. Photo credit: fruchtzwerg's world/ Flickr

This also means that the Arctic is warmer now than it was in what geologists call the early Holocene, the end of the last Ice Age—when the peak summer sunlight was roughly nine percent greater than it is today, according to Dr. Gifford Miller of the University of Colorado Boulder.

The mosses studied by Dr. Miller, of course, could feel nothing: they were dead. But they could tell a story, all the same.

The Arctic ice cap has been in constant retreat for the last century, and glaciers almost everywhere have been melting: there are fears that the process has begun to accelerate as greenhouse gases concentrate in the atmosphere.

But as the ice recedes, it exposes evidence of the past, preserved over the millennia in the natural deep freeze.

Creating a Timeline of Climate Change

The researchers used a technique called radiocarbon dating to establish that the mosses had been screened from the elements for at least 44,000 to 51,000 years. Since radiocarbon dating is only accurate for about 50,000 years, the mosses could have been buried for perhaps 120,000 years, since the last “interglacial” when the polar regions experienced a natural thaw.

Miller and colleagues report in Geophysical Research Letters that they did their fieldwork on Baffin Island in the Arctic Circle, and measured the radiocarbon ages of the dead mosses in at least four different locations.

They were careful to pick their 145 samples within one meter of the receding ice cap. Since the ice is receding at two or three meters a year, they could be sure the plant tissues had just been exposed that season.

Since the plants could only have taken root in sunlight, they were evidence that the exposed terrain was once free of ice. They became silent witnesses, telling researchers about the changes through time in the frozen North.

“The key piece here is just how unprecedented the warming of Arctic Canada is," said Miller. "This study really says the warming we are seeing is outside any kind of known natural variability, and it has to be due to increased greenhouse gases in the atmosphere.” 

Recent Decades Critical

Since radiocarbon clocks can only tick for so long, the Colorado team used ice cores to provide clues to the climate history of Baffin Island: each winter’s snowfall and summer melt is preserved in the icepack and like the growth rings in a tree provides a calendar of annual change.

The last time temperatures on Baffin Island were as high as today was about 120,000 years ago. About 5,000 years ago, after a mellow period in the early Holocene, the Arctic began to cool again, and stayed cool until the beginning of the last century.

“Although the Arctic has been warming since about 1900, the most significant warming in the region didn’t really start until the 1970s,” said Dr. Miller.

“And it really is in the last 20 years that the warming signal from that region has been just stunning," Miller concluded. "All of Baffin Island is melting, and we expect all of the ice caps to disappear, even if there is no additional warming."

An Extinction Rebellion protester outside the Bank of England on Oct. 14, 2019 in London, England. John Keeble / Getty Images

By Jessica Corbett

In another win for climate campaigners, leaders of 12 major cities around the world — collectively home to about 36 million people — committed Tuesday to divesting from fossil fuel companies and investing in a green, just recovery from the ongoing coronavirus pandemic.

Read More Show Less

EcoWatch Daily Newsletter

Demonstrators from several environmental groups including Extinction Rebellion and Sunrise Movement demand broad action at a youth-led climate strike near City Hall on December 6, 2019 in New York City. Scott Heins / Getty Images

By Jacob Wallace

This story is published as part of StudentNation's "Vision 2020: Election Stories From the Next Generation" reports from young journalists that center the concerns of diverse young voters. In this project, working with Dr. Sherri Williams, we recruited young journalists from different backgrounds to develop story ideas and reporting about their peers' concerns ahead of the most important election of our lives. We'll continue publishing two stories each week over the course of September.

In the speech she gave at the People's Climate March in Washington in 2017, Jansikwe Medina-Tayac, then 15, told a crowd of thousands, "This [climate change] is not just an environmental issue. This is a race issue, this is an immigration issue, this is a feminist issue."

Read More Show Less

Trending

Rep. Sean Casten, D-Ill., places a flag at the COVID Memorial Project's interfaith memorial service to honor the 200,000 people who died due to coronavirus on the National Mall on Sept. 22, 2020. Tom Williams / CQ-Roll Call, Inc. via Getty Images

The United States passed 200,000 deaths due to COVID-19 Tuesday and experts warn that number may double before the end of the year as an autumn surge in cases starts, according to USA Today.

Read More Show Less
People Have the Power - VOTE 2020

Climate-action nonprofit Pathway to Paris first launched in 2014 with an "intimate evening" of music and conversation after the People's Climate March in New York City.

Read More Show Less
Heo Suwat Waterfall in Khao Yai National Park in Thailand. sarote pruksachat / Moment / Getty Images

A national park in Thailand has come up with an innovative way to make sure guests clean up their own trash: mail it back to them.

Read More Show Less

Support Ecowatch