Greenland Glaciers On the Edge
FILE - A boat navigates at night next to large icebergs near the town of Kulusuk, in eastern Greenland on Aug. 15, 2019. A sharp spike in Greenland temperatures since 1995 showed the giant northern island 2.7 degrees (1.5 degrees Celsius) hotter than its 20th-century average, the warmest in more than 1,000 years, according to new ice core data. (AP Photo/Felipe Dana, File)
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New ice core analysis shows sharp Greenland warming spike

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By SETH BORENSTEIN

A sharp spike in Greenland temperatures since 1995 showed the giant northern island 2.7 degrees (1.5 degrees Celsius) hotter than its 20th-century average, the warmest in more than 1,000 years, according to new ice core data.

Until now Greenland ice cores -- a glimpse into long-running temperatures before thermometers -- hadn’t shown much of a clear signal of global warming on the remotest north central part of the island, at least compared to the rest of the world. But the ice cores also hadn’t been updated since 1995. Newly analyzed cores, drilled in 2011, show a dramatic rise in temperature in the previous 15 years, according to a study in the journal Nature.

“We keep on (seeing) rising temperatures between 1990s and 2011,” said study lead author Maria Hoerhold, a glaciologist at the Alfred Wegener Institute in Germany. “We have now a clear signature of global warming.”

It takes years to analyze ice core data. Hoerhold has new cores from 2019 but hasn’t finished studying them yet. She expects the temperature rise to continue as Greenland's ice sheet and glaciers have been melting faster recently.

“This is an important finding and corroborates the suspicion that the ‘missing warming’ in the ice cores is due to the fact that the cores end before the strong warming sets in,” said climate scientist Martin Stendel of the Danish Meteorological Institute, who wasn’t part of the research.

The ice cores are used to make a chart of proxy temperatures for Greenland running from the year 1000 to 2011. It shows temperatures gently sloping cooler for the first 800 years, then wiggling up and down while sloping warmer until a sharp and sudden spike hotter from the 1990s on. One scientist compared it to a hockey stick, a description used for other long-term temperature data showing climate change.

The jump in temperature after 1995 is so much larger than pre-industrial times before the mid-19th century that there is “almost zero” chance that it is anything but human-caused climate change, Hoerhold said.

The warming spike also mirrors a sudden rise in the amount of water running off from Greenland's melting ice, the study finds.

What had been happening in Greenland is that natural weather variability, undulations because of an occasional weather system called Greenland blocking, in the past had masked human-caused climate change, Hoerhold said.

But as of about 25 years ago, the warming became too big to be hidden, she said.

Past data also showed Greenland not warming as fast as the rest of the Arctic, which is now warming four times faster than the global average. But the island appears to be catching up.

Ice core data for years showed Greenland acted a bit differently from the Arctic. That’s likely because of Greenland blocking, Hoerhold said. Other scientists said as a giant land mass Greenland was less affected by melting sea ice and other water factors compared to the rest of the Arctic, which is much more water-adjacent.

Hoerhold’s team drilled five new cores near old cores so as to match established ice core records. They use the difference between two different types of oxygen isotopes found in the ice to calculate temperature, using an already established formula that is checked against observed data.

Hoerhold and outside scientists said the new warming data is bad news because Greenland’s ice sheet is melting. In fact, the study ends with data from 2011 and the next year had a record melt across Greenland and the island’s ice loss has been on high since then, she said.

“We should be very concerned about North Greenland warming because that region has a dozen sleeping giants in the form of wide tidewater glaciers and an ice stream,” said Danish Meteorological Institute ice scientist Jason Box. And when awakened, it will ramp up melt from Greenland, he said.

And that means “rising seas that threaten homes, businesses, economies and communities,” said U.S. National Snow and Ice Data Center Deputy Lead Scientist Twila Moon.

© Copyright 2023 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed without permission.

©2023 GPlusMedia Inc.

7 Comments
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Just when I finished reading the opposite in a different article.

0 ( +4 / -4 )

Just when I finished reading the opposite in a different article.

What was the primary source for that different article? the whole point of an article like this one being trust worthy is that is being supported by actual scientific data and the expert opinion of professionals in the field. If someone without a valid authority says the opposite without any data to support that conclusion then there is no point in considering both articles as equivalent. That is called a false equivalence.

-3 ( +1 / -4 )

Why would you ask that? I read it, not you.

Because it can be a mistake to draw equivalences between a well supported article like the one here and something just baselessly claiming something different.

Seeing how you can't even reference that opposite article this seems to be the case.

That's the whole point because you believe it to be? We need more than that of course.

So your argument is that you ignore that articles written with serious scientific basis are much more trustworthy than others without evidence to support them?

That would be a problem much more serious than drawing false equivalences, and can explain being mistaken so frequently, having unreliable, invalid or plainly false sources causes this.

-3 ( +1 / -4 )

what a verified news dated back thousand years,how somebody cant trust and believe in it???

sorry abt my irony :)

if any chance get email contact of author of article as I wish to get lotto winning numbers from him.dont worry we share profit fifty fifty :)

0 ( +2 / -2 )

what a verified news dated back thousand years,how somebody cant trust and believe in it???

It is a very reliable method. The ice is in layers allowing individual years to be identified. According to the article the scientists measured the concentrations of two different oxygen isotopes in the ice to determine what the average temperature was. The concentrations of those isotopes are affected by outside temperature in known ways. This gives you a way to measure temperatures decades in the past.

You can also see soot layers that were the result of big volcanic eruptions. If you count back ice layers in glaciers and sea ice in various parts of the world and find soot at the same year or years you can tell the extent of a particular volcanic eruption. Ice cores tell a lot of tales. When I was a kid in the 1960s I spent endless hours reading about this stuff in National Geographic. Ice core science is not something new.

1 ( +2 / -1 )

Interesting how information in other articles tell a contrasting story.

-2 ( +1 / -3 )

Interesting how information in other articles tell a contrasting story.

As said before, if the "other articles" are much more unreliable and not supported by any scientific source that would explain completely the discrepancy, choosing better sources can help in not forming mistaken opinions.

-1 ( +0 / -1 )

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