Scientists report that temperatures in Greenland have not been this high for at least 1,000 years

CNN
–

as humans Tampering with the planet’s thermostatScientists work together Greenland History by drilling into ice cores to analyze how they function The climate crisis has affected island country over the years. The deeper they dug, the further back in time they went, allowing them to separate fluctuations in temperatures that were natural from those that were human-caused.

After years of research on the Greenland Ice Sheet – which CNN visited when the cores were dug up – reported Wednesday scientists at Nature magazine that temperatures there were the warmest in at least the past 1,000 years – the longest period of time for which ice cores can be analysed. They found that between 2001 and 2011, the average temperature was 1.5 degrees Celsius warmer than it was during the 20th century.

The report’s authors said human-caused climate change played a significant role in the dramatic rise in temperatures in the critical Arctic region, where melting ice has a significant global impact.

“Greenland is currently the largest contributor to sea level rise,” Maria Horhold, lead author of the study and a glaciologist at the Alfred Wegener Institute, told CNN. “And if we continue to address carbon emissions as we do now, by 2100 Greenland will have contributed up to 50 cm to sea level rise and this will affect millions of people living in coastal areas.”

Weather stations along the edge of Greenland’s ice sheet have detected that its coastal regions are warming, but scientists’ understanding of the effects of warming there has been limited by a lack of long-term observations.

Understanding the past is important to prepare for future consequences, Horhold said.

“If you want to say something is global warming, you need to know the natural variation before humans actually interact with the atmosphere,” she said. “For that, you have to go to the past – to the pre-industrial era – when humans weren’t emitting [carbon dioxide] in the atmosphere. ”

During pre-industrial times, there were no weather stations in Greenland collecting temperature data like today. That’s why scientists have relied on paleoclimate data, such as ice cores, to study warming patterns in the region. The last robust analysis of the Greenland ice core ended in 1995, Horhold said, and that data did not detect warming despite climate change already evident elsewhere.

She added, “With this extension to 2011, we can show that, ‘Well, there is indeed a warming.'” “The warming trend has been there since 1800, but we had strong natural diversity masking that warming.”

Before humans start to burp Fossil fuel emissions In the atmosphere, temperatures near 32 degrees Fahrenheit in Greenland are unheard of. But recent research shows that the Arctic region was Warming four times faster from the rest of the world.

Scientists say significant warming in the Greenland ice sheet is nearing a tipping point, which could be causing it Catastrophic melting. Greenland has enough ice that if it all melted, it could raise global sea levels about 24 ftAccording to NASA.

Although the study only covered temperatures during 2011, Greenland has seen extreme events since then. In 2019, there was an unexpected hot spring and July heat wave It caused almost the entire surface of the ice sheet to melt and precipitate 532 billion tons of ice in the sea. Scientists then reported that global sea level would rise by 1.5 mm as a result.

Then in 2021, rain fell on top of Greenland – nearly two miles above sea level – for the first time registered. Then the warm air created heavy, dumping rain 7 billion tons of water on the ice sheet, enough to fill the reflecting pool on the National Mall in Washington, D.C. about 250,000 times.

With these extremes happening in Greenland so often, Horhold said the team will continue to monitor changes.

“Every degree counts,” said Horhold. “At some point, we will go back to Greenland and continue to expand these records.”