By Andrew Curry , Science.  Excerpt: The Black Death is the single most deadly documented pandemic in human history. In 1347 C.E., it spread from a few Italian port cities to nearly every corner of Europe, killing tens of millions of people within a decade and eliminating more than half the continent’s population. In a paper published today in  Communications Earth & Environment , researchers argue that cool weather  spurred by previously unidentified volcanic eruptions  set into motion a deadly chain of events. ...The authors of the new paper suggest volcanic eruptions a few years before the plague’s rapid spread played a role, by pushing plumes of sulfur high into the atmosphere that cooled parts of Europe and caused harvests to fail around the Mediterranean. These failures, in turn, forced Italian cities to import large quantities of grain from the plague-wracked Black Sea region—along with infected fleas, capable of subsisting on grain dust in the cargo holds...

By Bob Berwyn , Inside Climate News.  Excerpt: Add to the long list of global warming concerns that melting ice caps could trigger more volcanic eruptions. Worse, researchers said Monday at a scientific conference in Prague, the increasing volcanic activity holds the potential for a range of long-term climate feedbacks, as some volcanoes in Antarctica could accelerate ice melt from below while others could be so explosive that they send climate-altering material into the upper layers of the atmosphere. The research funded by the National Science Foundation studied the chemistry of rocks at six volcanoes in the Chilean Andes, where the scientists were able to detail changes in the magma below the ice or underground over the millennia of the most recent ice age, and to document how volcanic activity increased when the ice melted. University of Wisconsin–Madison geoscientist  Brad Singer , who led the research, said there are clear signs that thick ice caps act as lids on vo...

By Madeline Reinsel , Eos/AGU.  Excerpt: A slow climate feedback loop may be bubbling beneath Antarctica’s vast ice sheet. The continent...includes volcanic giants such as  Mount Erebus and its iconic lava lake . But at least 100 less conspicuous volcanoes dot Antarctica, with many clustered along its western coast. Some of those volcanoes peak above the surface, but others sit several kilometers beneath the Antarctic Ice Sheet. Climate change is causing the ice sheet to melt, raising global sea levels. The melting is also removing the weight over the rocks below, with more local consequences. Ice sheet melt has been shown to  increase volcanic activity in subglacial volcanoes  elsewhere on the globe.  Coonin et al.  ran 4,000 computer simulations to study how ice sheet loss affects Antarctica’s buried volcanoes, and they found that gradual melt could increase the number and size of subglacial eruptions. The reason is that this unloading of ice sheets reduc...

By Richard Stone , Science.  Excerpt: The 1831 eruption of Zavaritskii volcano in the Kuril Islands sparked cropped failures and famines. The first sign of an impending cataclysm in the summer of 1831 was an eerie dimming of the Sun, which for days appeared bluish green across the Northern Hemisphere. In the ensuing weeks, foul weather and a long cold snap triggered crop failures and famines in India and Japan. The instigator was long presumed to be a climate-altering plume from a major eruption, but the volcano’s identity had been one of the great unsolved mysteries of volcanology. “It’s like a whodunit,” says Clive Oppenheimer, a volcanologist at the University of Cambridge. At long last, the culprit has been unmasked in a report out today in the Proceedings of the National Academy of Sciences. A team led by volcanologist William Hutchison of the University of St. Andrews describes sulfur isotopes and glassy shards of ash deposited in ice core layers dated to 1831 that trace back...

By Skyler Ware , Eos/AGU.  Excerpt: Massive volcanic eruptions have reshaped Earth and its climate at several points in history. New research suggests that long after these surface eruptions ceased, carbon dioxide (CO 2 ) dissolved in underground magmas could have slowly escaped to the surface. This “cryptic carbon” may have contributed to prolonged periods of warming, slow climate recovery, and mass extinctions. ...extensive volcanism has occurred in conjunction with periods of climate disruption throughout Earth’s history: Large igneous provinces emitted large volumes of greenhouse gases such as CO 2  into the atmosphere, raising temperatures. These events were also sometimes accompanied by major biological changes. The eruptions of the Siberian Traps 252 million years ago coincided with massive biodiversity loss, known as the end-Permian mass extinction, or the Great Dying. But during that event, temperatures and CO 2  levels remained high for about 5 million years aft...

By Rebecca Owen , Eos/AGU.  Excerpt: On 15 January 2022, the underwater volcano Hunga Tonga–Hunga Ha‘apai erupted, unleashing a powerful  tsunami  that destroyed homes and caused four deaths throughout Tonga. Another lasting effect of this event—the  largest underwater explosion  ever recorded by modern scientific instruments—was the  huge amount of aerosol and water vapor  plumes it launched skyward.  Schoeberl et al.  examined how Hunga’s eruption affected climate in the Southern Hemisphere over the following 2 years. They found that in the year following the eruption, the cooling effect from the volcanic aerosols reflecting sunlight into outer space was stronger than the warming caused by water vapors trapping heat in the atmosphere. But most of the volcano’s effects had dissipated by the end of 2023....  Full article at https://eos.org/research-spotlights/atmospheric-effects-of-hunga-tonga-eruption-lingered-for-years . 

https://www.science.org/content/article/massive-lava-outburst-may-have-led-snowball-earth By Maia Wei-Haas, Science.  Excerpt: About 717 million years ago, a climate catastrophe struck the planet, as temperatures plunged and glaciers enveloped the globe. The cause of this “Snowball Earth” episode has been mysterious, but it took place around the same time as a massive outburst of volcanism. Many researchers thought there might be a connection. But the timing was uncertain. Now, more precise dates, reported last month in  Earth and Planetary Science Letters  (EPSL) and in November 2022 in  Science Advances , show the eruptions preceded the Snowball Earth event by 1 million to 2 million years. The lag points to a particular way the fire could have triggered the ice: through a chemical alteration of the fresh volcanic rocks known as weathering, which sucks carbon dioxide (CO 2 ) from the atmosphere, turning down the planetary thermostat. The studies highlight the power ...

https://eos.org/research-spotlights/volcanoes-future-climate-effects-may-exceed-standard-estimates By Sarah Stanley , Eos/AGU.  Excerpt: When volcanoes erupt, they often spew large amounts of  sulfur dioxide  into the atmosphere. This toxic, foul-smelling gas may then form tiny sulfate particles that particularly in the stratosphere, can  influence Earth’s climate  for months to many decades. In modeling future climate change, scientists have therefore incorporated the effects of volcanic eruptions. However,  Chim et al.  now show that there is a 95% chance that volcanic eruptions between 2015 and 2100 will release more sulfur dioxide into the atmosphere than standard climate models currently assume....

https://eos.org/research-spotlights/do-volcanoes-add-more-carbon-than-they-take-away By Saima May Sidik , Eos/AGU.  Excerpt: In a new study,  Zhong et al.  discovered that a volcano in northeast China emits a small net amount of carbon each year. Over geological timescales, that could have a significant impact on our planet’s carbon cycle. Volcanic areas continue to emit carbon dioxide long after  eruptions  are over. Conversely, atmospheric carbon dioxide (CO 2 ) is constantly locked away into minerals on Earth’s surface through a process called  silicate weathering . Whether volcanoes release more CO 2  through degassing or capture more CO 2  through silicate weathering is an open question. The authors of the new study   investigated whether the Changbaishan volcanic area in northeast China is a net source or sink of atmospheric carbon. The region has been active for at least 2.7 million years, but it has not erupted since 1903, making the...

https://eos.org/articles/tonga-eruption-may-temporarily-push-earth-closer-to-1-5c-of-warming By J. Besl , Eos/AGU.  Excerpt: The underwater eruption of Hunga Tonga–Hunga Ha‘apai sent megatons of water vapor into the stratosphere, contributing to an increase in global warming over the next 5 years. When Hunga Tonga–Hunga Ha‘apai (HTHH) erupted in January 2022, it shot the standard volcanic cocktail of ash, gas, and pulverized rock into the sky. But the eruption included one extra ingredient that’s now causing climate concerns: a significant splash of ocean water. The underwater caldera shot  146 metric megatons  of water into the stratosphere like a geyser, potentially contributing to atmospheric warming over the next 5 years, according to a new study published in  Nature Climate Change .... Source:    

https://eos.org/articles/centuries-old-archive-reveals-far-flung-impacts-of-major-eruptions By  Shannon Banks , Eos/AGU.  Excerpt: In 1815, an Earth-shattering explosion sent roughly  130 cubic kilometers  of gaseous fumes, ash, and rocks high into the atmosphere above the Indonesian island of Sumbawa. Mount Tambora had blown its top. Temperatures tanked worldwide as sooty debris circulated in the skies of the Northern Hemisphere, blocking the Sun’s rays. The chilling effects lasted through 1816—later dubbed the “Year Without a Summer.” ... Alice Bradley  and her team of undergraduate researchers at Williams College are studying how Tambora and other major volcanic eruptions affected the climate in New England. Their source material is a weather data set that dates back more than 2 centuries to the Tambora eruption. It has been updated daily by Williams staff and students ever since. ...According to the team’s analysis, daily low temperatures after the Tambora a...

https://news.berkeley.edu/2022/09/12/mega-eruptions-linked-to-most-mass-extinctions-over-past-500-million-years/ By  Robert Sanders , UC Berkeley News.  Excerpt: Mass extinctions litter the history of life on Earth, with about a dozen known in addition to the five largest ones — the last of which, at the end of the Cretaceous Period 66 million years ago, killed off the dinosaurs and 70% of all life on Earth. A new study, led by scientists at Dartmouth College in New Hampshire, concludes that most of these mass extinctions had one thing in common: They occurred after mega-eruptions that spewed volcanic lava and toxic gases for hundreds of thousands of years, and some for as long as a million years. The analysis linking mass extinctions throughout Earth’s history with major eruptions, characterized by lava and gas spilling from perhaps dozens of volcanoes and long fissure vents, confirms what many geologists have suspected for years. The most well-known mass extinction, referred...

https://www.science.org/content/article/massive-undersea-eruption-filled-atmosphere-water By Nathaniel Scharping, Science Magazine.  Excerpt: On 15 January, Tonga’s Hunga Tonga-Hunga Ha'apai volcano erupted under the sea, rocking the South Pacific nation and sending tsunamis racing around the world. The eruption was the  most powerful ever recorded , causing an atmospheric shock wave that circled the globe four times, and sending a plume of debris more than 50 kilometers into the atmosphere. ...The ash and gasses punching into the sky also shot billions of kilograms of water into the atmosphere, a new study concludes. That water will likely remain there for years, where it could eat away at the ozone layer and perhaps even warm Earth. ...In all,  the plume shot approximately 146 billion kilograms of water into Earth’s stratosphere , an arid layer of the atmosphere that begins several miles above sea level, the authors report this month in Geophysical Research Letters...

https://www.science.org/content/article/hidden-carbon-layer-may-have-sparked-ancient-bout-global-warming By Paul Voosen, Science Magazine.  Excerpt: There is no perfect parallel in Earth’s past for present-day climate change—human-driven warming is simply happening too fast and furiously. The closest analog came 56 million years ago, when over the course of 3000 to 5000 years, greenhouse gases soared in the atmosphere, causing at least 5°C of warming and pushing tropical species to the poles. The cause of the Paleocene-Eocene Thermal Maximum (PETM) has long been debated, with researchers invoking exotic mechanisms such as catastrophic releases of methane from the sea floor or even asteroid strikes. But over the past few years, evidence has mounted for a more prosaic culprit: carbon-spewing volcanoes that emerged underneath Greenland as it tore away from Europe. Now, researchers have found signs of an effect that would have supercharged the warming effect of the volcanoes, making th...

https://eos.org/articles/did-volcanoes-accelerate-the-fall-of-chinese-dynasties By  Tim Hornyak , Eos/AGU.  Excerpt: After analyzing ice cores and historical documents, researchers found a link between eruptions and political change in China over the past 2 millennia. Researchers in China, Europe, and the United States ...have found that volcanic eruptions (as well as conflict) may have contributed to dynastic collapse because they cooled the climate and affected agricultural production.…

https://www.sciencemag.org/news/2021/08/massive-volcanoes-could-cool-earth-more-warming-world By  Paul Voosen , Science Magazine.  Excerpt: ...Before humanity started in on its planet-altering course, volcanoes were one of the biggest climate players. Over the long term, they belched carbon dioxide from Earth’s interior, causing warming. But in the short term, their sulfur gases often react with water to form highly reflective particles called sulfates, triggering spells of global cooling. Dark smudges of ash littering ice cores—our best evidence of these early eruptions—are a dim reflection of the wild weather left in their wake. But the opposite is also true, it turns out: Climate can have a big impact on volcanoes. In the new study, Thomas Aubry, a geophysicist at the University of Cambridge, and colleagues combined computer simulations of idealized volcanic eruptions with a global climate model. They simulated the response to plumes released from midsize and large volcanoe...

https://eos.org/articles/food-security-lessons-from-the-vikings Source: By  James Dacey , Eos/AGU.  Excerpt: Scandinavian societies of the first millennium adapted their farming practices to volcano-driven climate changes. ...During this half millennium between 300 and 800, northern Europe experienced cold climates  driven by volcanoes  spewing gases and dust into the atmosphere, which reduced the amount of solar radiation reaching Earth’s surface. ...The new research finds evidence that a community in Norway responded to this climate turbulence by regularly adapting its cereal production and animal husbandry practices. It is one of the first studies from a multidisciplinary project called Volcanic Eruptions and their Impacts on Climate, Environment, and Viking Society in 500–1250 CE ( VIKINGS ).... 

https://www.nytimes.com/2020/11/18/science/extinction-global-warming.html Source:  By Lucas Joel, The New York Times.  Excerpt: Paleontologists call it the Permian-Triassic mass extinction, but it has another name: “the Great Dying.” It happened about 252 million years ago, and, over the course of just tens of thousands of years, 96 percent of all life in the oceans and, perhaps, roughly 70 percent of all land life vanished forever. The smoking gun was ancient volcanism in what is today Siberia, where volcanoes disgorged enough magma and lava over about a million years to cover an amount of land equivalent to a third or even half of the surface area of the United States. But volcanism on its own didn’t cause the extinction. The Great Dying was fueled, two separate teams of scientists report in two recent papers, by extensive oil and coal deposits that the Siberian magma blazed through, leading to combustion that released greenhouse gases like carbon dioxide and methane. “The...

https://www.nytimes.com/2020/06/22/science/rome-caesar-volcano.html Source:  By Katherine Kornei, The New York Times.  Excerpt: Scientists have linked historical political instability to a number of volcanic events, the latest involving an eruption in the Aleutian Islands. ...This eruption was one of the largest of the last few millenniums, Dr. McConnell and his collaborators concluded, and the sulfate aerosols it created remained in the stratosphere for several years. These tiny particles are particularly good at reflecting sunlight, which means they can temporarily alter Earth’s climate. “They’ve created, for a short term, global cooling events,” said Jessica Ball, a volcanologist at the California Volcano Observatory, who was not involved in the research. ...There’s good evidence that the Northern Hemisphere was colder than normal around 43 B.C. Trees across Europe grew more slowly that year, and a pine forest in North America experienced an unusually early autumn freeze...

https://www.sciencemag.org/news/2019/12/how-volcanic-eruption-helped-create-modern-scotland Source:   By Sid Perkins, Science Magazine. Excerpt: Over seven terrible years in the 1690s, crops failed, farming villages emptied, and severe famine killed up to 15% of the entire population of Scotland. The so-called Scottish ills (named after the biblical plagues) ushered in an era of crippling economic conditions. Soon after, the formerly independent nation joined Great Britain. Now, researchers suggest volcanic eruptions thousands of kilometers away may have helped spark this political transformation. Scientists have long known that volcanoes can alter Earth’s climate. During large eruptions, light-scattering droplets of sulfuric acid reach the stratosphere and spread around the globe, reflecting some of the Sun’s radiation back into space and cooling the planet. Such cold spells can last from several months to several years—and they can help trigger droughts and crop failures. The...