Dust in East Greenland ice samples provides new insight into climate change
Scientists have developed a method that can map the advancement of glaciers in cold periods and their melting in warmer periods. The data may be used to predict sea level rise.
A major threat that may emerge as a consequence of global warming is the increase in coastal flood risk driven by melting glaciers that lead to sea level rise. Therefore, reliable assessments of sea level variability are crucial for effective adaptation strategies.
Partially supported by two EU-funded projects, TiPES and ICE2ICE, a team of researchers examined East Greenland’s ice core dust record to shed light on climate and atmospheric conditions. Their findings were published in the journal ‘Nature Communications’.
An ice core is a cylinder-shaped sample of ice drilled from a glacier. The analysis of its physical and chemical properties can reveal past variations in climate ranging back to hundreds of thousands of years. A news release by the University of Copenhagen’s Niels Bohr Institute explains: “The ice is composed of annual layers, like the growth rings in a tree, so the distribution of large and small dust particles can be linked to the advancement and melting of the ice.”
According to lead author Dr Marius Folden Simonsen, while the end of the Ice Age where the ice cap is shrinking is well explained scientifically, it’s hard to obtain data on the period before the Ice Age. “The ice is an extremely strong natural force, so it grinds away everything when advancing. But with the new method, we have data on the advancement of the ice. All of a sudden, we have a link to information on how quickly we enter an ice age, in a way we never used to have,” Dr Simonsen says.
As noted in the same news release, the findings of the new method can be utilised “to compare the reaction in the masses of ice to changes in the atmospheric content of greenhouse gasses like CO2.” The results are important for climate models that are used to forecast the rise in sea level “because the models must be tested by comparison to reality,” as noted by Dr Simonsen. “And in the new method we’ve acquired an anchor point in a period about which not much scientific knowledge existed.” The research team hopes to use the new method at other locations to collect more data on past changes of glaciers, with new drill sites planned in north-east Greenland and Canada.
The ongoing TiPES (Tipping Points in the Earth System) project was set up to clarify and explain the dynamics and thresholds of climate change tipping points (TPs), beyond which rapid changes can occur without any additional forcing. The TiPES factsheet states: “The project will identify subsystems that may exhibit abrupt transitions, and couplings between them, by focussing on paleoclimatic records and abrupt transitions therein.” It adds: “Novel methods to detect Early Warning Signals of forthcoming TPs, and to make skilful predictions on their basis, will be developed.”
The ICE2ICE (Arctic Sea Ice and Greenland Ice Sheet Sensitivity) project ended in July 2019. It focused on “the cause and future implications of past abrupt climate change in Greenland, the main hypothesis being that Arctic and sub-Arctic sea ice cover is key to understand past and future Greenland temperature and ice sheet variations,” as noted on CORDIS.
For more information, please see:
TiPES projectICE2ICE project