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“Extinction Rebellion”, in English “Rebellion against extinction”, is the name of a group of climate activists calling for radical climate protection in Europe with civil disobedience. It is assumed that the more CO₂ enters the atmosphere and warms up climate change, the more likely a mass extinction of species will occur on earth.
The dreaded climate apocalypse would not be the first of its kind, the researchers explain in a study that appeared in the journal “Nature Geoscience.” For the first time, they were able to completely reconstruct one of the largest mass extinctions in Earth’s history 252 million years ago, and draw troubling conclusions for our present time.
The research team from the GEOMAR Helmholtz Center for Marine Research in Kiel and the German Research Center for Geosciences GFZ examined the disaster at the end of the so-called Permian Age. At that time, the effect of greenhouse gases got completely out of control and made it impossible for marine animals, coral reefs, insects and mammals to survive on land. Overall, 95 percent of all marine life and about 70 percent of land animals and plants disappeared. The mass extinction of the time occurred long before an asteroid wiped out the dinosaurs.
390,000 billion tons of CO₂ were released into the atmosphere.
According to the researchers’ findings, the causes of the mass extinction are gigantic volcanic activities in what is now Siberia. Volcanic eruptions that lasted for several thousand years released enormous amounts of carbon into the air. In total, nearly 360,000 trillion tons of CO₂ were released into the atmosphere, according to the study authors. “That’s more than 40 times the amount of carbon that has been burned since the industrial revolution and also from the fossil fuels that are still in the ground,” says lead author Hana Jurikova of the Geomar Center in Kiel in an interview with SPIEGEL.
This enormous accumulation of CO₂ in the Earth’s atmosphere caused a kind of ecological domino effect. “We were able to show that the increase in CO₂ had devastating consequences for the earth’s climate and the ecosystem and that it ultimately destroyed most of the life on earth,” Jurikova said. Unlike previous studies on the disaster, the researchers now would have broken down in great detail the consequences of climate change for the ecosystem. This look into the past is a kind of warning, says Hana Jurikova. “We can use this mass extinction to see the ecological consequences of a rampant greenhouse effect.”
To do this, the scientists examined fossil calcareous shells of so-called brachiopods, which are shell-shaped organisms. The researchers reconstructed the rise in atmospheric CO₂ using isotopes of carbon and boron. Isotopes are a type of physical fingerprint; They can be used to retrospectively determine the age of objects, but also weather conditions.
According to the study, massive CO₂ emissions from volcanoes caused a strong greenhouse effect, causing extreme warming and acidification of the oceans. These effects are also occurring in the current climate crisis, although to a much lesser extent.
Today’s CO2 surge happens much faster
The chain of disasters is quite fragmented, but devastating: due to the high content of CO₂ in the atmosphere and acid rain, rocks and stones, for example, erode faster. Their remains were washed into the oceans and rivers faster and would have provided more nutrients such as phosphates and nitrates.
This would have led to the reproduction of certain plants and, in turn, fueled photosynthesis. As a result, the oxygen content in the sea has decreased extremely, similar to the strong growth of algae in a lake after a hot summer. But without oxygen there is no life; many animals and plants died. Acidification did the rest and destroyed coral reefs and decimated shellfish populations.
Marine biologist Hana Jurikova says that the volcanic eruptions of that time cannot be compared to the man-made emissions of today. The amounts are much lower overall. However, the accumulation of CO₂ in the atmosphere occurs today much faster than 250 million years ago. “However, our current anthropogenic emissions are about 14 times higher than the peak emissions during extinction,” says Jurikova. “A thousand years is nothing in terms of geological history,” says the researcher. “The 200 or so years since industrialization, on the other hand, is a minuscule period for such large amounts of CO₂.”
Furthermore, the consequences observed in the study are similar to current observations made by biologists and climate researchers: the land has already warmed by around one degree on average and the pH value in the sea is also changing: water is released of the entry of CO₂ into the atmosphere. but also more acidic in water.
