2004: Hollywood made paleoclimatology — the study of Earth’s ancient climate — pop-culture famous with scientist Jack Hall, who analyzes the Antarctic past only to discover an imminent Ice Age in Tomorrow’s Day. But this kind of work isn’t a Hollywood invention. Paleoclimatology is a way to understand the future and its consequences. Climate change. New research on Greenland’s ice sheet shows just how far into the future we can peer — and it isn’t a rosy picture.
Recent StudyPublished in the journal PLOS ONESimulated changes to the Greenland ice sheet — an immense body of ice spanning 1.63 million kilometers — between the last interglacial period 125,000 years ago and the year 2100.
“The evolution of the ice sheet in the past tells us that the response of ice volume to climate change is delayed by several millennia,” Hu YangThe study’s co-author, Dr. Judith Helmholtz, is a researcher at Alfred Wegener Institute Helmholtz Center for Polar and Marine Research. Inverse.
What’s new —Three key findings were identified by the scientists from their simulations that simulated the Greenland Ice Sheet over time.
- The ice sheet reached its maximum and minimum volumes around 17 to 18,000 years and 5 to 6,000 years ago, respectively — even though extreme climate change had begun occurring several thousand years prior to these dates.
- The scientists conclude changes to the Greenland ice sheet lagged behind the actual climate change events by “several millennia.”
- In more recent history, between 8,000 years ago and the pre-industrial era, the researchers find that Greenland’s climate grew colder, and the Greenland ice sheet also grew in volume until the second half of the twentieth century, even though temperatures began rising in the 1850s after the Industrial Revolution.
In other words, there was a lag in the effect of global warming on the ice sheet’s volume.
All of this means we won’t necessarily see Greenland’s ice sheet melt in real-time as global temperatures dangerously rise. Instead, we may have to wait many millennia for the full effects of climate changes on the ice sheets.
“The results show that [Greenland ice sheet] delayed the climate change in the past, and will delay human-induced climate change as well,” Yang says.
The study also reveals how past climate change — paleoclimate — has lingering effects on the present-day melting of the Greenland ice sheet.
“Its evolution is not only controlled by present climate changes but also influenced by past climate,” he adds.
How they made the discovery — Using various earth system and ice sheet models, including one created by the research team’s Alfred Wegener Institute, the researchers simulate changes to the volume of the Greenland ice sheet between 125,000 years ago and the year 2100.
“The current study qualitatively gives a picture of how ice sheets evolve in the past and will possibly evolve in the future,” Yang says.
Why it matters — Earth’s past informs the present, and there is no better evidence of that truism than the researchers’ chilling new findings on this massive Arctic ice sheet.
Scientists have already identified the link between Greenland and Greenland melting iceGlobal warming and the Arctic circle. We’re already seeing the effects of such ice melt as rising sea levels pose A threat imminentTo the coast cities
“Within this century, melting of the Greenland ice sheet could, in the worst case of warming, possibly increase the sea level by tens of centimeters,” Yang says.
According to this study, we might not experience the worst effects of ice melting in our lifetimes. This could lead us to underestimate the devastating impacts of climate change on this immense ice sheet and sea level rise.
“More significant sea-level rise from melting could be irreversible and last for several millennia, even if we can stop or reverse the warming,” Yang grimly concludes.
What’s next —There are some caveats as with any major initial discovery. Future work will need to address these.
Researchers acknowledge that their model underestimates warming temperatures by 1% Celsius. This could lead to an underestimation of the climate crisis’ impact on the Greenland ice sheets.
“The estimated amplitude of ice mass changes has large uncertainty,” Yang explains. “In the future, we would use better models and combine [on-ground] observations to reduce the uncertainty.”
However, simulations of ice sheets such as this one will continue being a critical method for accurately predicting long-term effects on sea-level rise from Greenland ice.
Researchers argue that if we are to understand the impact of climate change on ice melting, we must shift our timeline from centuries to millennia.
“The most worrying melting of [the ice sheet] will not occur within decades, or centuries — it could last for [a] thousand years,” Yang says.
AbstractUsing simulations from Alfred Wegener Institute Earth System Model, (AWI-ESM), transient climate forcing is used to simulate the Greenland Ice Sheet evolution from the last Interglacial (125 ka kiloyears prior to present) through 2100 AD using the Parallel Ice Sheet Model. We explore the impact of paleoclimate, particularly the Holocene climate on the present and future evolutions of the GrIS. Simulations of the past are in good agreement with reconstructions regarding the timing of the peaks and Greenland’s climate. The maximum and minimum ice volume at around 18–17 ka and 6–5 ka lag the respective extremes in climate by several thousand years, implying that the ice volume response of the GrIS strongly lags climate change. Given that Greenland’s climate was getting colder from the Holocene Thermal Maximum (i.e., 8 ka) to the Pre-Industrial era, our simulation implies that the GrIS experienced a background growth from the mid-Holocene to the industrial era. This background trend means that the GrIS continues to gain mass even though anthropogenic global warming began around 1850 AD. This observational evidence also supports the conclusion that mass loss of GrIS doesn’t occur before the late 20th Century. Our results demonstrate that the current evolution in the GrIS is not just controlled by current climate change, but also affects by paleoclimate and the particularly warm Holocene climate. We suggest that the GrIS was not in equilibrium during the entire Holocene. The slow response to Holocene weather needs to be represented in ice sheets simulations to accurately predict ice mass loss and sea level rise.