Relatively few people have been to the Arctic, and even fewer have set foot in Antarctica. Most of us rely on our imaginations and media to visualize these landscapes and the ways they are changing.
Research shows that the Arctic is warming four times faster than the global average. The sea ice is melting, exposing more open ocean and throwing the ecosystem out of balance. The story of Antarctica contains fewer details, but emerging trends are concerning to researchers.
Conceptualizing this change can be challenging for those of us who have only glimpsed Greenland from the airplane window, but for someone with firsthand experience, it’s eye-opening.
Melinda Webster , a research scientist at the University of Washington’s Applied Physics Laboratory, has visited the Arctic at least once a year since 2009, sometimes staying for as long as five months.
Webster is the lead author of a new research paper, published Sept. 2 in Nature Reviews Earth and Environment, that describes how sea ice has changed in the past 50 years.
Their analysis arrives as the world begins preparations for the fifth International Polar Year , a dedicated period of observation that will peak during the 2023 to 2033 season. International Polar years have occurred every 30 to 50 years since the late 1800s to advance polar research and track environmental change. The upcoming International Polar Year will occur just 25 years after the last, held in 2007, due to the acceleration of climate change.
“There aren’t many colors on Arctic sea ice. It’s a gradient of blues and grays; a stunning, stark icescape that makes you appreciate how harsh the environment is, and how fragile," Webster said. "The state of ice cover is both an indicator and an amplifier of climate change”.
What motivated this study?
Melinda Webster : We have known for a long time now that the extent, or area, and thickness of sea ice is declining, especially in the Arctic. But we wanted to take that a step further to examine the properties of the ice, especially perennial ice, which doesn’t completely melt away in summer. We updated trends for sea ice with 15 to 20 more years worth of data to understand how it has changed through the contemporary period. We also wanted to emphasize the divergent responses we see in the Arctic and Antarctica, and make recommendations for future research.
What did you discover?
MW : The Arctic sea ice melt season has gotten approximately seven and a half days longer since 1979, and this is mostly driven by sea ice forming later in the fall. This has sweeping implications for the global climate system. The superpower of sea ice is its high albedo, meaning that it reflects a lot of sunlight — somewhere between 60% and 90% — back into space. Dark ocean water, on the other hand, reflects just 7%. The open ocean absorbs much more sunlight than ice does, and with that absorption comes warming. In the fall, the ocean is too warm for ice to form and it is taking longer for that heat to dissipate.
The seasonal ice that ultimately forms is thinner, and easier to melt in the following spring and summer. So this creates a cycle of warming that reduces ice coverage and increases the amount of energy in our climate system over time.
What’s the deal with Antarctica?
MW : Antarctica is a land mass covered in ice and surrounded by water. The Arctic is an ocean surrounded by land. Although they share certain qualities, the two regions are very different from one another, with distinct responses to climate change. For a long time, the sea ice cover wasn’t declining in Antarctica, but in the last four years the sea ice cover experienced record losses.
Logistically, it’s a lot more difficult to deploy instruments in the Antarctic than the Arctic. The measurements we do have are less accurate because the Antarctica sea ice system is more complicated. But, we need to unravel these recent changes, which is a priority research area we identify in the paper.
What other impacts do you foresee these changes having?
MW : Another key result we presented is that snow cover on Arctic sea ice has gotten thinner and the sea ice itself is smoother. That has huge repercussions for polar bears and seals, as it impacts their ability to build dens for raising their young.
There’s also a connection to fisheries. Changes in sea ice cover also impact algae, which form the base of the food web. These algae are accustomed to very low light conditions, but thinner snow and ice let more light in and the algae are essentially getting sunburnt.
When you take an ecosystem that was adapted to an ice environment and introduce open ocean, it disrupts its regular functioning. The health of algae impacts the entire food web, which has important implications for fisheries in the sub-Arctic and Arctic. Less food might mean fewer fish, and that introduces a whole new set of concerns.
Are there any potential solutions?
MW : To mitigate climate change, you have to reduce greenhouse gas emissions. That’s at the center of the problem. There are various alternative geoengineering strategies floating around but little consensus on how safe and useful they are.
I think that it is critical to have international regulations that are shaped by representative communities on what kind of research we need before any geoengineering action is taken, if at all. Still, at the end of the day, geoengineering is a Band-Aid. We need to reduce greenhouse gas emissions to deal with the underlying cause of climate change instead of just treating its symptoms.
I’m optimistic about solutions for reducing emissions. Technological and scientific innovation are progressing at a rapid pace, which gives me hope about the future.
Co-authors include Stefanie Arndt of the University of Hamburg; Angela Bliss of NASA Goddard Space Flight Center; Sahra Kacimi of the Jet Propulsion Laboratory at California Institute of Technology; Ted Maksym of Woods Hole Oceanographic Institution; François Massonnet of Université Catholique de Louvain; Aku Riihelä of the Finnish Meteorological Institute and Takenobu Toyota of Hokkaido University.
This research was funded by the U.S. National Science Foundation, the U.S. Office of Naval Research, NASA, the Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, the University of Hamburg, the German Research Foundation, SnowCast, the DFG Emmy Noether Programme Project Snowflake and the Research Council of Finland.
For more information, contact Webster at melindaw@uw.edu .
Changes in Arctic and Antarctic sea-ice properties and processes
2-Sep-2026