Greenland’s Prudhoe Dome ice cap was completely gone only 7,000 years ago, study finds

Greenland ice sheet (east coast) [credit: Hannes Grobe @ Wikipedia]

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This makes alarmist claims of Earth today being ‘hottest for 100k years’ – or longer (“You’d have to go back to the last interglacial about 125,000 years ago to find temperatures significantly higher than temperatures of today”) – look more than a bit suspect, although some have previously called for more research. At the time the Prudhoe Dome ice cap melted ‘temperatures were around 3 to 5 degrees Celsius warmer than they are today’. But even the research here insists on blaming humans for today’s climate and recent warming, as if it’s something unique rather than part of a cycle of natural variations.
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The first study from GreenDrill—a project co-led by the University at Buffalo to collect rocks and sediment buried beneath the Greenland Ice Sheet—has found that the Prudhoe Dome ice cap was completely gone approximately 7,000 years ago, much more recently than previously known, says Phys.org.

These sediment-based records are rich sources of information that have enabled paleoclimate scientists to reconstruct past global temperatures, but they have important limitations.

For one, bottom currents and burrowing organisms can mix the sediment, blurring any short-term temperature spikes. For another, the timeline for each record is not known precisely, so when multiple records are averaged together to estimate past global temperature, fine-scale fluctuations can be canceled out.

Because of this, paleoclimate scientists are reluctant to compare the long-term record of past temperature with short-term extremes.
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When sediment is buried, electrons can become trapped inside its tiny mineral grains due to natural radiation and remain there until the sediment is exposed to light again, at which point they produce a measurable glow.

The intensity of that glow revealed that the Prudhoe Dome sediment was last exposed to daylight sometime between 6,000 and 8,200 years ago.

“This means Prudhoe Dome melted sometime before this period, likely during the early Holocene, when temperatures were around 3 to 5 degrees Celsius warmer than they are today. Some projections indicate we could reach those levels of warming at Prudhoe Dome by the year 2100,” says the study’s lead author, Caleb Walcott-George, Ph.D., a former UB graduate student and now assistant professor at the University of Kentucky.

Full article here.
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Image: Greenland ice sheet (east coast) [credit: Hannes Grobe @ Wikipedia]