2022 Updates from State of the Cryosphere Report
- The true rate of Arctic warming is three to four times faster than the global average, nearly double previous estimates, based on several decades of observational records . Arctic sea ice loss drives this cycle, increasing the amount of heat absorbed by the dark surface of the ocean. This feedback loop is most prominent in the Barents and Kara seas, where ocean warming has accelerated sea ice loss to unprecedented levels.
- The decline of sea ice in the Barents-Kara Seas alone may account for up to one-third of winter warming over the Tibetan Plateau. The tibetan Plateau holds thousands of glaciers and serves as the source for many major rivers, including the Yellow and Yangtze Rivers, providing water for 40% of the world’s population. Continued sea ice loss would exacerbate winter warming across nearly all regions of the Tibetan Plateau, endangering the reliability of seasonal water supply in much of China and southeast Asia. The rapid loss of Arctic sea ice may also intensify tem-perature and precipitation trends by 50% in Europe, North America, West Africa and South America.
- In addition to losing nearly three-quarters of summer sea ice volume since the early 1980s, the Arctic has lost one-third of its entire winter sea ice volume in the past 20 years, mainly due to the loss of thick, multi-year ice. This once-prevalent multi-year ice has been replaced with thinner “seasonal” ice, which melts completely each summer. Since 2019, rising global temperatures have thinned Arctic multi-year ice by 0.5 meters – decreasing its total remaining volume by one-sixth in only three years.
- This loss of multi-year sea ice also threatens Arctic marine life. Vulnerable regions such as the North Water polynya (NOW), a unique open-water ecosystem surrounded by sea ice between Greenland and Ellesmere Island in Canada, may no longer be able to serve as a winter refuge for keystone high Arctic mammals, or as central fishing and hunting ground for Inuit communities in the region as well as commercial fishing activities. Multiple lines of evidence now show increasing sea ice instability in this sector over the last two decades.
- Arctic sea ice helps protect the Alaskan coastline from open ocean waves generated by strong winds in the Beaufort Sea. During the winter, this sea ice cover prevents waves from reaching the coastline. Over the past forty years, the “open-water” season – the warm period each year without the seasonal sea ice cover – has lengthened by more than three months, resulting in a five-fold increase in annual wave power and exposing Alaskan coastlines to erosion and collapse.
- The first ice-free summer will be an event that the Arctic likely has not experienced since at least the Holocene spike in warming after the last ice age 8,000 years ago, and possibly not since the warm Eemian period 125,000 years ago. Today’s temperatures almost equal those during the Eemian, when sea level was 4–6 meters (13–20 feet) higher than today. This is the current trajectory of the Earth’s climate; and CO2 levels from human emissions today are higher than at any point in the last 3 million years.
Video 1: State of the Cryosphere: livestream presentation November 18, 2022 at COP27
Video 2: NOAA Arctic Report Card 2022: livestream presentation December 15, 2022 at COP27
