Sea ice has stopped growing: red alert for sea level

• • South Pole expansion hits sad record in 2023
  • A decade of repeating records
  • Cities like La Rochelle, Rouen or Liverpool threatened

The Earth is covered, at the South and North poles, with a thick layer of ice, the pack ice. Although it melts in summer, it rebuilds and gains ground in winter as temperatures drop. But in his latest report, the National Snow and Ice Data Center (NSIDC) alarm on weak ice expansion during the winter of 2023.

Scientists explain in particular that Antarctica has experienced an expansion “only” of 2.35 million square kilometers. Never had the expansion of the pack ice been so weak in the heart of winter. The previous record dates back to 2017.

The situation is similar on the other side of the globe. The level of ice expansion in the Arctic would be 13.67 million square kilometres. If the figure is much higher at the North Pole than at the South Pole, it is still below the averages over the period 1980-2010.

A historically small pack ice

Only the year 2018 will have been milder than 2023, resulting in less expansion of the sea ice in the Northern Hemisphere. A small consolation prize for the scientists who assure that these figures are the result of a long-term trend. For them, the recent physical modifications of the Sun cannot explain the record levels reached at the beginning of the year 2023.

If the Sun’s cycle is no longer the same (our star is more active than before), this excess power has little impact on the Poles. The aurora borealis and australis are more numerous but their radiation does not warm the atmosphere for as long as a year.

These natural phenomena alone cannot explain the changes observed in the level of sea ice expansion over the past decade. With ever less expansion and ever faster melting, it is ultimately the level of the oceans and the entire marine ecosystem that is threatened.

Rising waters: what consequences?

In its 2019 report, the IPCC focused on the consequences of rising sea levels. According to scientific forecasts, the average sea level should rise by 46 to 110 centimeters by 2100 (depending on the scenarios). A change that may seem insignificant, but which risks upsetting the coasts of the whole world.

In July 2015, a geological study stated that a variation in global temperature of two degrees could raise sea levels by six meters. Such a change has already been observed at the end of the last ice age. Arriving today, he could wipe cities like Liverpool, Rouen, La Rochelle or Amsterdam off the map.

With a rise in water of “only” three meters, a scenario deemed “improbable, but possible” by the IPCC, more than half of the Netherlands would be under water. The World Bank estimates that global warming and rising sea levels will lead to the displacement of 216 million people before 2050.