In the heart of Greenland, temperatures have been hotter for at least a millennium, with 1.5 degrees higher than in the 20th century in the decade from 2001 to 2011 and global warming reaching the central part of the island as well. This is indicated by the study published in the journal Nature and led by the German Alfred Wegener Institute, which reconstructed the climate history of Greenland from the year 1000 to 2011 thanks to ice cores of unprecedented length and quality. The results surprised the researchers, who had not expected such a noticeable difference in temperature compared to earlier, even in the most inland areas of the island.
The Greenland ice sheet, which is up to 3,000 meters high and several kilometers thick, plays a fundamental role in the global climate system. Given the vast amounts of water stored in the ice, about 3 million cubic kilometers, the melting and consequent rise in sea levels is considered a point of no return: if global emission rates remain unchanged, it can indeed be expected that the ice sheet will increase the average sea level by 2100 um raise about 50 centimeters.
The researchers led by Maria Hörhold measured the concentrations of oxygen isotopes (atoms with a nucleus with the same number of protons but a different number of neutrons) in ice cores, which vary with the temperatures at the time the ice formed. The results made it clear that the warming has now reached the heart of the island: “These data – says Hörhold – show that the warming in the period between 2001 and 2011 differs significantly from the natural fluctuations that have been observed in the last 1,000 years”. .