Younger Arctic sea ice much more vulnerable to melting

Younger and thinner ice continues to make up more and more of the total sea ice extent in the Arctic. Since this ice has less volume, it it much more susceptible to complete melting out by the end of the melt season compared to the thicker, older sea ice.

The result is a continued downward trend in Arctic sea ice extent, especially during the melt season. As this thinner ice melts out, it leaves growing areas of open water, which has a lower albedo compared to snow and ice. The decrease in albedo means that more of the sun's energy is absorbed at the surface during the summer, which leads to increasing temperatures in the region.

The NSIDC image above compares the change in Arctic sea ice age during the late winter of 1985 with that of 2023. Back in 1985, older and thicker sea ice (red, yellow and green) made up a significant percentage (about 50 percent) of the total amount of sea ice in the region at that particular time. Fast forward to the same period in 2023 and the change is dramatic. Only about 10 percent of the total sea ice is old and thick, while younger and thinner ice (bluer shades) makes up more than 70 percent of the extent.

Once again, looking at the latest Arctic sea ice extent as of April 25 (below), we can see that this year continues to run well below the 1981-2010 median, below the record low year of 2012 and even on the outside edge of the interdecile range.

Keep in mind, even though the sea ice extent is still running below 2012, we will not know for a few months whether or not that record will be in jeopardy.