New estimates using sheet modeling show that Greenland’s speed Ice loss this century could be faster than in any century in the past 12,000 years.When the last ice age ended.
Scientists reconstructed ancient climates to build models, and validated the models against real-world measurements of the current and past sizes of glaciers.
The study brought together climate modelers, ice core scientists, remote sensing experts, and paleoclimate researchers. The team used an ice sheet model to simulate changes in the southwestern section of the Greenland Ice Sheet from the beginning of the Holocene epoch 12,000 years ago to 2100, 80 years later. Data from the ice core were used to create temperature and precipitation maps of the study area to drive ice sheet model simulations back to 1850, and other published climate data from that time were used to drive the simulations.
Scientists tested the accuracy of the model by comparing the model’s simulation results with past measurements. The modeled results were in good agreement with data from actual measurements of the ice sheet from satellite and aerial surveys in recent decades, as well as with field work that identified the ancient boundaries of the ice sheet.
“By measuring beryllium-10 in the rocks above the moraine, we have constructed a very detailed geological history of how the edge of the southwest Greenland ice sheet has moved over time.” Co-author Nicolás Young said.PhD, Associate Research Professor at LDEO. “Moraines are large piles of debris that you find in the landscape that mark the former edge of a glacier or ice sheet. The beryllium-10 measurements tell us how long that rock and moraines have been there, so they tell us exactly when the glacier was there and deposited that rock. Surprisingly, the model reproduced the geologic reconstruction really well. This gave us confidence that the glacier model was working well and giving meaningful results. You can model whatever you want, and the model will always give you an answer, but you need a way to check that the model is working properly.”
Although the project focused on southwest Greenland, the study found that changes in the rate of ice loss there were closely linked to changes in the overall ice sheet.
