Archives par mot-clé : Mass Extinction

better to know...?, Biodiversity

Remember when they told you climate change was causing a ‘mass extinction’? Never mind!

by A. Watts, Dec 2, 2025 in WUWT

From the University of Arizona and the “Emily Litella er, Greta Thunberg School of Climate Attribution” comes this breath of fresh air. BTW, Willis was right.

Extinction rates have slowed across many plant and animal groups, study shows

Prominent research studies have suggested that our planet is currently experiencing another mass extinction, based on extrapolating extinctions from the past 500 years into the future and the idea that extinction rates are rapidly accelerating.

A new study by Kristen Saban and John Wiens with the University of Arizona Department of Ecology and Evolutionary Biology, however, revealed that over the last 500 years extinctions in plants, arthropods and land vertebrates peaked about 100 years ago and have declined since then. Furthermore, the researchers found that the past extinctions underlying these forecasts were mostly caused by invasive species on islands and are not the most important current threat, which is the destruction of natural habitats.

The paper argues that claims of a current mass extinction may rest on shaky assumptions when projecting data from past extinctions into the future, ignoring differences in factors driving extinctions in the past, the present and the future. Published in the journal Proceedings of the Royal Society of London, the paper is the first study to analyze rates, patterns and causes of recent extinctions across plant and animal species.

For their study, Saban and Wiens analyzed rates and patterns of recent extinctions, specifically across 912 species of plants and animals that went extinct over the past 500 years. All in all, data from almost 2 million species were included in the analysis.

“We discovered that the causes of those recent extinctions were very different from the threats species are currently facing,” said Wiens, professor of ecology and evolutionary biology. “This makes it problematic to extrapolate these past extinction patterns into the future, because the drivers are rapidly changing, particularly with respect to habitat loss and climate change.”

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climate and geology

Low Volcanic Temperature Ushered in Global Cooling and the Thriving of Dinosaurs

by Tohoku University, Japan, Feb 1, 2022  in WUWT

Researchers in Japan, Sweden, and the US have unearthed evidence that low volcanic temperatures led to the fourth mass extinction, enabling dinosaurs to flourish during the Jurassic period.

Large volcanic eruptions create climatic fluctuations, ushering in evolutionary changes. Yet it is the volcanic temperature of the eruption that determines whether the climate cools or warms.

Since the emergence of early animals, five mass extinctions have taken place. The fourth mass extinction occurred at the end of the Triassic Period – roughly 201 million years ago. This mass extinction saw many marine and land animals go extinct, especially large-body, crocodilian-line reptiles known as pseudosuchia. Approximately 60-70% of animal species disappeared. As a result, small bodied dinosaurs were able to grow and prosper.

Scientists think the fourth mass extinction was triggered by the eruptions in the Central Atlantic Magmatic Province – one of the largest regions of volcanic rock. But the correlation between the eruption and mass extinction has not yet been clarified.

Using analysis of sedimentary organic molecules and a heating experiment, current professor emeritus at Tohoku University, Kunio Kaiho and his team demonstrated how low temperature magma slowly heated sedimentary rocks, causing high sulfur dioxide (SO2) and low carbon dioxide emissions (CO2).

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climate and geology, only geology

Asteroid, climate change not responsible for mass extinction 215 million years ago

by Todd McLeish, May 27, 2020 U. of RhodeIsland in PhysOrg

A team of University of Rhode Island scientists and statisticians conducted a sophisticated quantitative analysis of a mass extinction that occurred 215 million years ago and found that the cause of the extinction was not an asteroid or climate change, as had previously been believed. Instead, the scientists concluded that the extinction did not occur suddenly or simultaneously, suggesting that the disappearance of a wide variety of species was not linked to any single catastrophic event.

Their research, based on paleontological field work carried out in sediments 227 to 205 million years old in Petrified Forest National Park, Arizona, was published in April in the journal Geology.

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