The sudden warming has long been a mystery to scientists around the world. Over the course of a few thousand years, the temperature on Earth rose by between five and eight degrees. Many theories have been speculated about. Everything from the impact of a large meteorite to the emission of greenhouse gases in the earth’s surface has been discussed. But now researchers may have found out both where and how the sudden climate change happened: A giant underwater volcanic eruption off the coast of Nordland. Drilled into the seabed Last summer, the international research vessel JOIDES Resolution set course for the Vøring Plateau in the Norwegian Sea. Here they have drilled down through several hundred meters of seabed to retrieve 55 million-year-old rock samples. – This was what we were looking for and hoped to find, says geologist Sverre Planke about the findings. He was one of two captains on board the ship. Geologist Sverre Planke has helped lead the research work off the coast of Nordland. Here he is in front of glowing lava at a volcano in Iceland. Photo: Private – We have been working on this for many years: looking at connections between volcanism and rapid climate change. It was Forskning.no that first mentioned the findings. 20 years of work Already in 2004, Planke and his colleagues published the hypothesis that volcanic eruptions in the Norwegian Sea could be the cause of the drastic increase in the globe’s temperature. The eruptions occurred as Greenland slid westwards, away from Norway, and in the direction of present-day North America. The Vøring plateau is favorable for carrying out geological investigations as the sedimentary layers that lie above the volcanic remains are only a couple of hundred meters thick. Often these lie under several kilometers of sediments. Graphics: Egil Ursin As the continents drifted apart, lava erupted from the Earth’s interior. This led to large emissions of greenhouse gases. – The gases were formed when a lot of volcanic material entered sediment basins where greenhouse gases were formed. These gases were then released through large pipe structures on the seabed. The researchers have now mapped around 700 of these in the Norwegian Sea. – The sea boiled Through seismic surveys, it has been established that there are huge craters under the seabed, but it has never been possible to date and describe these precisely – until now. – Here we have rocks that show that there is a simultaneity with the emissions 55 million years ago. So now you can document this event in a completely different way, which is why this is very important. When the volcano Eyjafjallajökull erupted in 2010, 15 cubic kilometers of lava came up from the earth’s interior. During the eruption 55 million years ago, scientists estimate that as much as one million cubic kilometers of lava was released. Photo: EMMANUEL DUNAND / Afp Planke says that charred wood and pollen have been found in the rock samples, which suggests that the area was in shallow water at the time. – It was as if the sea boiled during the eruption. – A window into a possible future Kikki Kleiven is director of the Bjerknes Center for Climate Research at the University of Bergen. Climate researcher Kikki Flesche Kleiven is director of the Bjerknes Center at the University of Bergen. Photo: Stian Sørum Røkenes / news She says that many climate scientists are studying previous warming periods on the globe to better understand today’s climate change. And there are clear parallels with what happened 55 million years ago, and the emissions that are happening today. – At the time, the CO₂ level changed quickly, but it changes much faster today. That is the biggest difference. The rate at which we humans pump CO₂ into the atmosphere is ten times higher than during the warm period. Warm Period PETM An abbreviation for the Paleocene-Eocene Thermal Maximum Estimated to have occurred 55.5 million years ago The temperature of the globe rose by between 5 and 8 degrees Celsius during a period of 20-50,000 years. The warm period lasted an estimated 200,000 years before the temperature decreased. Several theories have been discussed as the cause: Large emissions of gas hydrates, areas with a lot of coal that have started to burn, large forest fires, meteor impacts, permafrost that has melted and volcanic activity in the Atlantic Ocean. The CO₂ level in the atmosphere is measured in parts per million (ppm). 55 million years ago the level reached 1000 ppm. Today it is 418 ppm. . – With the emission levels we have now, we can reach 1,000 ppm within 140 years, says Kleiven. – We are afraid that with very high emissions, both 2-3-4 degrees of warming may pass. Then we are approaching the warming of 55 million years ago, but it is happening much faster. Thus, the warm period is contrasted with the highest emission scenarios of the UN climate panel. – It is a window into a possible future. But despite the fact that the temperature on Earth rose by over five degrees 55 million years ago, no signs of mass death of species on Earth have been seen. – That is true, but we must bear in mind that it happened over several thousand years. Species and ecosystems can adapt if the changes happen slowly. – I quite often hear that “It has always been warmer before”. But then we have to put it in a time perspective. That something happens over many thousands of years is very different from if it happens in 150 years.
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Researchers close to answers to mysterious climate disaster outside Sandnessjøen – news Nordland
