The political news cycle is becoming increasingly frantic and depressing. Since the below-sea ice article will be buried, aren’t they all?; I thought the folks who follow the climate emergency on DK would want to know this important piece of the global warming puzzle. We learn together.
ICYMI, there is more evidence of increasing radiative forcing warming the oceans.
Derek Smith, University of Michigan, writes the presser for the University of Michigan, noting that new research shows that the Arctic has lost roughly a quarter of its cooling power over forty years, while the world has lost fifteen percent.
Using satellite measurements of cloud cover and the solar radiation reflected by sea ice between 1980 and 2023, the researchers found that the percentage decrease in sea ice's cooling power is about twice as high as the percentage decrease in annual average sea ice area in both the Arctic and Antarctic. The added warming impact from this change to sea ice cooling power is toward the higher end of climate model estimates.
When we use climate simulations to quantify how melting sea ice affects climate, we typically simulate a full century before we have an answer," said Mark Flanner, professor of climate and space sciences and engineering and the corresponding author of the study published in Geophysical Research Letters. "We're now reaching the point where we have a long enough record of satellite data to estimate the sea ice climate feedback with measurements."
The Arctic has seen the largest and most steady declines in sea ice cooling power since 1980, but until recently, the South Pole had appeared more resilient to the changing climate. Its sea ice cover had remained relatively stable from 2007 into the 2010s, and the cooling power of the Antarctic's sea ice was actually trending up at that time.
That view abruptly changed in 2016, when an area larger than Texas melted on one of the continent's largest ice shelves. The Antarctic lost sea ice then too, and its cooling power hasn't recovered, according to the new study. As a result, 2016 and the following seven years have had the weakest global sea ice cooling effect since the early 1980s.
The remaining sea ice in the Arctic is weaker and less reflective due to the surface pooling of meltwater and increasing rainfall.
The Antarctic has more knowledge gaps than the Arctic. The environment is brutal and difficult to reach and study. Satellite data measurements fill in those gaps. Antarctic land temperatures have recently set records for bitter colds, but most danger to the ice is under the surface.
Alisher Duspayev, the first author, noted that sea ice loss in 2016 "boosted the warming feedback from sea ice loss by 40%." The data must be added to climate models if the findings are accurate.
The study: Earth's Sea Ice Radiative Effect From 1980 to 2023