The effects of global warming in the Arctic are so severe that the region is shifting to a different climate, one characterized by less snow and ice and more characteristic of open water and rain, scientists said on Monday.
Already, he said, sea ice has dropped so much in the Arctic that even in an extremely cold year it won’t be as much as it was decades ago. The researchers said two other features of the region’s climate are seasonal air temperatures and a change in the number of days of rain instead of snow.
The Arctic is among the parts of the world most affected by climate change, with rapidly rising temperatures, permafrost and other effects in addition to the shrinking of sea ice. Laura Landrum and the National Center for Atmospheric Research in Boulder, Colo. K. Laura Landrum and Marika M. The study by Holland is an attempt to bring to context the developments in the region.
“Everyone knows the Arctic is changing,” Dr. Climat, a climate scientist and lead author of the study, published in the journal Nature Climate Change. Landrum said. “We really wanted to determine if this was a new climate.”
In other words, he said, “Has the Arctic changed so rapidly and so rapidly that the new climate cannot be inferred from the recent past?”
Using years of observational data from the field and computer models, researchers found that sea ice is already in a new climate, in effect: the amount of ice is consistently lower in recent years than in the worst year for ice Would also be expected in the mid-20th century.
Arctic sea ice has declined by nearly 12 percent per decade since satellite measurements began in the late 1970s, and the 13 lowest sea ice years since 2007. A record or near-record low for snow is expected this year, which will be set by the end of this month as the summer period ends.
For the days of fall and winter air temperatures and rain versus snow, simulations found that the transition to a new climate is occurring more slowly, with this change expected to be completed by the middle of the century.
Overall, Drs. “We are starting to get to the point where we can no longer know what to expect,” Landrum said.
Jennifer Kay, a climate scientist at the University of Colorado who was not involved in the research, said the new study built on previous people who saw less climatic elements.
“Nice to see all those variables,” Dr. K. he said. And the determination of the timing of different innings is an interesting contribution.
But scientists have known for a long time that fundamental changes were taking place in this field. “We know what used to happen,” Dr. K said. “We call it the ‘new Arctic’ because it is not the same.”
Dr. Landrum said Arctic communities are already suffering from the changes. Villages of some coastal Alaska origin are forced to consider relocation. Other changes are affecting the food supply. Warmer storms that bring rain to existing snow, for example, can cause starvation of animals rely on native groups.
“Arctic climate change is not for them in the future,” she said. “it snow.”
Dr. Landrum said the climate model used in the study simulated the future in a world where greenhouse gases had higher planetary-warming emissions. He provides some fodder for optimism.
“We still have the opportunity to change how fast the Arctic develops,” he said, “if we change our emissions.”
“You just can’t give up. If you work hard and make some changes, chances are you’ll have some dramatic effects.”
Another study released on Monday reported that two Antarctic glaciers that have long been a concern for scientists over their ability to contribute to sea level development may be in worse condition than before Huh.
Thewaites and Pine Island glaciers are rivers of ice that merge into the ocean with ice moving slowly from the West Antarctic ice sheet to the interior of the continent, where it melts and raises sea levels. The movement of the two glaciers has intensified in recent decades, causing more ice loss from the interior due to the melting of hot water beneath the glaciers.
However with acceleration, however, full melting of this part of the West Antarctic Sheet may take centuries. The new study, published in the Proceedings of the National Academy of Sciences, analyzed satellite imagery and found cracks and other signs of stress damage to glaciers. ‘Ice shelves, major shores floating on water. The paper’s authors wrote this evidence of damage is the first sign of ice shelves structurally weakening, a process that can end the disintegration of shelves and even the rapid glacial flow of ice into the ocean . The authors stated that incorporating these loss processes into models of ice-sheet dynamics is important for more accurate estimation of potential sea-level rise.