It is widely accepted that atmospheric pO2 < 1 ppm before the Great Oxidation Event. Yet a recent study found fossil micrometeorites (MMs) containing the oxidized iron species wüstite (FeO) and magnetite (Fe3O4) formed 2.7 billion years ago (Ga). How these MMs became oxidized is uncertain. Abundant O2 in the upper atmosphere and iron oxidation by CO2 have been suggested. However, photochemical reactions cannot produce sufficient O2, and oxidation by CO2 can only produce FeO, each individually failing to explain the formation of Fe3O4-only MMs. Using an oxidation model of iron MMs including photochemistry, we show that a >32% CO2 Archean atmosphere and different entry angles can generate the Fe3O4-only and Fe-FeO mixed composition MMs that have been discovered. Oxidation happens in two stages: by CO2 under brief melting, then by O2. Our results challenge existing constraints on Earth’s atmospheric CO2 concentration at 2.7 Ga and support a warm Late Archean despite the ‘faint young Sun’.
Could Antarctica’s ‘Doomsday Glacier’ meet its doom within 3 years?
“Time is melting away for one of Antarctica’s biggest glaciers, and its rapid deterioration could end with the ice shelf’s complete collapse in just a few years,” alarmist researchers warned at a virtual press briefing on Dec. 13, 2021 at the annual meeting of the American Geophysical Union (AGU)–a once outstanding professional society, but now a shill for the left.
Above is the first sentence of the article titled “Antarctica’s ‘Doomsday Glacier’ could meet its doom within 3 years,” not what we would expect to see from a once reputable source, the AGU. It warns us that in a few years, the world’s largest glacier, about the size of Florida, will melt and raise ocean levels by up to 3 meters (about 10 ft). It then tells us that the glacier is melting from below because the surrounding ocean waters have been warmed “thanks to human-induced climate change.” Finally, it tells us that a team of more than 100 scientists from the USA and the UK have been studying the Thwaites glacier and sharing their findings with scientists worldwide.
The article then explains that the Thwaites is not melting from above, but “the melting is coming from below,” from the warmed-up oceans that have been warmed by human-made CO2 and the greenhouse effect. The bulk of the article then proceeds to detail the forecasted consequences around the world:
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This team may not have even been communicating with each other. Almost a decade earlier, geologists were seeing evidence of volcanoes in a known active tectonic plate boundary, buried under the glacier and the oceans. Before 2017, at least 47 volcanoes were found in western Antarctica and around the area of the Thwaites glacier. In 2017 the Guardian reported that an additional 91 volcanoes had been found along the western shores of Antarctica, with some sitting under the Twaites glacier itself. See the article “Scientists discover 91 volcanoes below Antarctic ice sheet.”
The tropical (20N-20S) anomaly for June was -0.36 deg. C, which is the coolest monthly anomaly in over 10 years, the coolest June in 22 years, and the 9th coolest June in the 44 year satellite record.
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La géologie, une science plus que passionnante … et diverse
