Climate: scientific warning cry on irreversible warming – world

The planet may have already crossed a tipping point towards irreversible global warming, with consequences “cascading” from Greenland to the Great Barrier Reef, the head of the largest scientific expedition ever led on Tuesday warned. in the north Pole.

“Only the assessment of the next few years will determine whether we can still save the Arctic sea ice present all year round through coherent climate protection, or whether we have already crossed this important tipping point of the climate system”, underlined German Markus Rex in Berlin, eight months after returning from the international mission in the Arctic.

Markus Rex, the head of the science mission at the North Pole. (AFP)

A mission of almost a year

For almost a year, international teams have collected exhaustive data, especially during the months when their ship has drifted in the ice of the North Pole, which must deliver valuable information on climate change.

One can really wonder if we have not already walked on this mine and already triggered the start of the explosion.

“The disappearance of summer ice in the Arctic is one of the first mines in the minefield, one of the tipping points we first trigger when we push warming too far,” said Markus. Rex at a press conference with German Minister of Education and Research Anja Karliczek. However, “we can really wonder if we have not already walked on this mine and already triggered the start of the explosion,” insisted this climatologist and physicist, a leading scientist in the study of the Arctic.

If this tipping point has already been crossed, it can trigger adverse “cascading” effects, he also warned, and “further worsen warming such as the disappearance of the Greenland ice cap or the thawing of areas still larger areas of the arctic permafrost ”. The threat also hangs over the old glaciers. “Today we also don’t know if we can save the Great Barrier Reef” in Australia, he said.

The sea ice is melting at “a dramatic speed”

On the return of the Polarstern icebreaker of the German Alfred-Wegener Institute to its home port of Bremerhaven, in northwestern Germany, on October 12, the head of the mission called MOSAIC had already uttered a cry alarm concerning the pack ice, claiming that it was melting at “a dramatic speed”.

(FILES) In this file photo taken on October 12, 2020, people watch as German icebreaker and research vessel "Polarstern" arrives at the harbor of nothern German town of Bremerhaven, after a

The retreat of the sea ice in summer is considered by scientists to be “the epicenter of global warming”, according to Markus Rex. He then claimed to have seen in summer “large surfaces of liquid water almost to the pole, surrounded by ice which was riddled with holes due to massive melting”. Tuesday, he even assured that the pack ice had retreated “faster during the spring of 2020 than since the beginning of the measurements” of the pack ice and that the extent of ice during the summer was half less than decades earlier.

We may be the last generation to be able to see the Arctic with ice floes in the summer

For her part, sea ice specialist Stefanie Arndt lamented that “we are perhaps the last generation to be able to see the Arctic with sea ice in the summer”. However, this pack ice, she underlined, is “an important living space for polar bears”. Experts have collected more than 150 terabytes of data as well as more than a thousand ice samples.

Several hundred experts and scientists

During 389 days, the mission led jointly by 20 different countries and with a budget of 140 million euros studied at the same time the atmosphere, the ocean, the sea ice and the ecosystem to collect data evaluating the impact of climate change on the region and the whole world. In total, several hundred experts and scientists stayed there, taking turns on the ship which slid with the ice according to the polar drift, this ocean current which flows from east to west in the Arctic Ocean.

Shaken up by the pandemic, the mission was saved at the last minute in the spring of 2020. The Polarstern zigzagged a total of 3,400 km, i.e. a distance as the crow flies of 1,923 km, ending up at one point at 1,500 km away from the nearest settlement area.

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