The climate doomsday machine constantly insists that sea ice at the two poles is shrinking inexorably and that the Arctic will soon be ice-free in the summer. But the latest data puts the kibosh on those predictions. The maximum winter Arctic ice extent last month was no different from 2023, and the minimum summer 2024 extent in the Antarctic, although lower than the long-term average, was higher than last year.

Satellite images of Arctic sea ice extent in February 2024, one month before its winter peak (left image), and Antarctic extent at its summer minimum the same month (right image), are shown in the figure below. Sea ice shrinks during summer months and expands to its maximum extent during the winter. The red lines in the figure denote the median ice extent from 1981 to 2010.

Arctic summer ice extent decreased by approximately 39% over the interval from 1979 to 2023, but was essentially the same in 2023 as it was in 2007. Arctic winter ice extent on March 3, 2024 was 11% lower than in 1979, when satellite measurements began, but slightly higher than in 2023, as indicated by the inset in the figure below.

Arctic winter maximum extent fluctuates less than its summer minimum extent, as can be seen in the right panel of the figure which compares the annual trend by month for various intervals during the satellite era, as well as for the low-summer-ice years of 2007 and 2012. The left panel shows the annual trend by month for all years from 2013 through 2024.

What is noticeable about this year’s winter maximum is that it was not unduly low, despite the Arctic being warmer than usual. According to the U.S. NSIDC (National Snow & Ice Data Center), February air temperatures in the Arctic troposphere, about 760 meters (2,500 feet) above sea level, were up to 10 degrees Celsius (18 degrees Fahrenheit) above average.

The NSIDC attributes the unusual warmth to a strong pressure gradient that forced relatively warm air over western Eurasia to flow into the Arctic. However, other explanations have been put forward for enhanced winter warming, such as the formation during non-summer seasons of more low-level clouds due to the increased area of open water compared to sea ice. The next figure illustrates this effect between 2008 and 2022.

Despite the long-term loss of ice in the Arctic, the sea ice around Antarctica had been expanding steadily during the satellite era up until 2016, growing at an average rate between 1% and 2% per decade, with considerable fluctuations from year to year. But it took a tumble in 2017, as depicted in the figure below.

Note that this figure shows “anomalies,” or departures from the February mean ice extent for the period from 1981 to 2010, rather than the minimum extent of summer ice in square km. The anomaly trend is plotted as the percent difference between the February extent for that year and the February mean from 1981 to 2010.

As can be seen, the summer ice minimum recovered briefly in 2020 and 2021, only to fall once more and pick up again this year. The left panel in the next figure shows the annual Antarctic trend by month for all years from 2013 through 2024, along with the summer minimum (in square km) in the inset. As for the Arctic previously, the right panel compares the annual trend by month for various intervals during the satellite era, as well as for the high-summer-ice years of 2012 and 2014.

Antarctic sea ice at its summer minimum this year was especially low in the Ross, Amundsen, and Bellingshausen Seas, all of which are on the West Antarctica coast, while the ice cover in the Weddell Sea to the north and along the East Antarctic coast was at average levels. Such a pattern is thought to be associated with the current El Niño.

A slightly different representation of the Antarctic sea ice trend is presented in the following figure, in which the February anomaly is shown directly in square km rather than as a difference percentage. This representation illustrates more clearly how the decline in summer sea ice extent has now persisted for seven years.

The overall trend from 1979 to 2023 is an insignificant 0.1% per decade relative to the 1981 to 2010 mean. Yet a prolonged increase above the mean occurred from 2008 to 2017, followed by the seven-year decline since then. The current downward trend has sparked debate and several possible reasons have been advanced, not all of which are linked to global warming. One analysis attributes the big losses of sea ice in 2017 and 2023 to extra strong El Niños.

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