When scientists talk about rising sea levels, they are referring to land-based ice that ends up in the water. Sea ice is frozen ocean and, while it doesn’t change sea levels, it plays a very important role in regulating our climate. First off, sea ice acts as a natural mirror. It’s light in color and so it’s reflective and can bounce back solar radiation. Once sea ice melts, the darker ocean water below absorbs rather than reflects the Sun’s rays, heating up the water even more, in a positive feedback loop, leading to more and more warming.
Sea ice expels salt, since salt doesn’t freeze, leading to denser water below that sinks and becomes part of the mass movement of water called the global ocean conveyor, which helps regulate energy in the global climate system. Finally, algae, a food source for krill, clings to the bottom of the ice. This krill, in turn, is a food source for whales, seals, penguins, and other birds. A whole ecosystem depends on the ice!
Antarctica’s sea ice is changing. We just entered the year 2023, so, looking back at 2022, average annual temperature over the entire continent was 1.5 degrees Celsius warmer than usual, when comparing with a 30-year climate record. The tip – the Peninsula – was even warmer, at nearly 3 degrees Celsius warmer than usual. And the sea ice? It’s the lowest (spatial) extent since satellite record keeping began in 1979.
Up in the Arctic, land-based glaciers on the western side of Svalbard are experiencing increased melting. Data from more than 5,500 aerial images taken by a Norwegian mapping project in the 1930s are now proving to be invaluable to scientists, to be able to compare how the glaciers look nearly a century later. Curious to learn more? And to learn how we can deal with climate change in S.M.A.R.T. (specific, measurable, achievable, realistic, and time-constrained) ways? Join a webinar I’ll be giving later today at 12 PM mountain time. Register here: https://us02web.zoom.us/webinar/register/WN_IPJXI2bGT7aSqMAhms1DhA
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