Greenland ice breaks 1,000-year record and heralds disaster eight decades from now

Between 2001 and 2011, the temperature of the Greenland ice sheet was 1.5C warmer than the 20th-century average, making it the warmest decade of the last millennium, according to a study of island temperatures. essential for the global climate.

To carry out the study, the conclusions of which were published Wednesday in the journal Nature, the scientists reconstructed temperatures in north-central Greenland and the ice melt rates between the years 1,100 and 2,100.

Due to its size and the large amount of water it stores (about three million cubic kilometres), the Greenland ice sheet plays a critical role in the global climate system.

For example, if the global emissionsthe melting of Greenland is predicted to raise global sea levels by 50 centimeters in the year 2100, something catastrophic for the entire planet.

For years the weather stations located on the edge of this ice cap (on the coast) record an increase in temperatures but understanding the effects of global warming in the central island is limited by a lack of long-term observations.

Now, the study published in Nature and led by experts from the Alfred Wegener Institute and the Helmholtz Center for Polar and Marine Research (AWI) presents compelling evidence that the effects of global warming have reached remote and elevated areas of north-central Greenland.

“The time series we recovered from the ice cores continuously collects data for more than 1,000 years, from the year 1000 to 2011. These data show that warming from 2001 to 2011 differs in aspects from natural variations over the past millennium. this was to be expected in light of global warming, we were surprised at how noticeable this difference was,” he says Maria Horhold, AWI glaciologist and lead author of the study

In an unprecedented effort, Hörhold and his colleagues drilled ice cores of five locations analyzed in the 1990s to reconstruct the evolution of north-central Greenland ice temperature between 1100 and 2011.

The temperatures were reconstructed using a single method: measuring the concentrations of stable oxygen isotopes within the ice, which vary as a function of the temperatures prevailing at the time of ice formation.

Also, the team reconstructed the evolution of the thaw.

All this allowed them to collect an important dataset with which to improve the understanding of the melting dynamics of the ice sheet and better calculate projections of future sea level rise.

The study concludes that recent temperatures in north-central Greenland are record breaking the highest in the last thousand years.

On average, the reconstructed temperature for 2001-2011 was 1.7°C warmer than for 1961-1990 and 1.5°C warmer than for the entire 20th century.

The authors state that these temperatures are the result of a combination of natural substitution and global warming started in the 18th century by human activity, and they say this warming has caused a thaw in north-central Greenland that could increase as more ice is lost from the sheet.

Finally, they conclude that the climate of the Greenland ice sheet is very disconnected from the rest of the Arctic “which has been shown to have its own dynamic,” defends Thomas Laepple, an AWI researcher and co-author of the paper.

The authors believe that the dynamics of Greenland itself are due to the fact that the height of the island’s ice sheet is more influenced by patterns of atmospheric circulation compared to other parts of the Arctic. EFE extension