Volcanos & C.C.

[Amo]

https://news.climate.columbia.edu/2021/03/09/volcano-impacts-global-precipitation/

Interesting quoted article below, from link above. About volcano eruptions and climate effects or change.

Volcanoes May Have Large, Lasting Impacts on Global Precipitation

Large tropical volcanoes have caused some of the world's most destructive natural disasters, with eruptions spewing out massive streams of harmful gases and hot debris that can wipe out everything in their path. But, what about wider impacts on global climate? Large eruptions are well known to temporarily cool the planet, but the picture is less clear when it comes to changes in the global distribution of rainfall.

In a new study, a team of researchers from Columbia University's Lamont-Doherty Earth Observatory, the University at Albany and other institutions have used natural climate archives such as tree rings to better understand big eruptions' global hydroclimate impacts over the past 1,000 years. Their results suggest that changes often are significant, and have persisted for more than a decade. Most notably, they observed abnormally dry conditions over tropical Africa, Central Asia and the Middle East, and unusually wet conditions over Oceania and the South American monsoon regions. The results were published this week in the Proceedings of the National Academy of Sciences.

The team identified all the known tropical eruptions in the past millennium that were larger than 1991's Mount Pinatubo eruption, the biggest of the last 100 years. Then, using natural proxies that record local moisture conditions over time, they analyzed the aftereffects.

"We have not had a major volcanic eruption in 30 years, so I think we tend to forget how large of a societal disruption they can cause," said coauthor Matthias Vuille, a professor at the University at Albany. (Pinatubo caused average global temperature to drop 1 degree F over a 15-month period—the result of sulfur compounds high in the air that prevented solar energy from reaching the surface.) "Our proxy product adds new, real-world data to estimate the responses on a global scale, which suggests these eruptions can cause much larger and prolonged wet and dry anomalies than we initially believed."

"The trees, and the other natural climate archives were there to see these volcanic eruptions happen. It's not a theoretical construct," said coauthor Jason Smerdon, at Lamont-Doherty. "This was the first time we were able to use this new proxy product as an estimate of volcanic climate responses in the past, and the picture it paints has yielded surprises in terms of how large and persistent the hydroclimatic impacts of volcanism can be."

The new dataset used in the study, called the Paleo Hydrodynamics Data Assimilation (PHYDA) product, was created through a long-term project involving Lamont-Doherty scientists. PHYDA is a publicly available global reconstruction of temperature and hydroclimate conditions over the last 2,000 years, estimated by combining information from a climate model and a global collection of 2,591 tree-ring records, 197 coral and sponge records, 153 ice-core isotope records, 26 cave-sediment records, 10 lake-sediment records and one marine-sediment record.

Using PHYDA, the researchers compared their new proxy-estimated changes with those derived exclusively from an existing climate model, which showed less drastic results. They say that understanding discrepancies between the proxy-based product and a stand-alone climate model are critical for projecting how future volcanic eruptions may affect global climate, especially considering the added impacts of human-influenced climate change.

"If you look at past centuries and the frequency of large volcanic eruptions through history, it is very likely that we'll see a similar-sized eruption before the end of this century, possibly more than one," said lead author Ernesto Tejedor of UAlbany. "We believe our findings serve as an important warning that affected communities must not only think about immediate impacts, but that volcanic eruptions could lead to long-lasting changes in climate."

The study's other authors are Nathan Steiger of Lamont-Doherty and Hebrew University of Jerusalem, and Roberto Serrano-Notivoli of the Autonomous University of Madrid. The study was supported by the U.S. National Science Foundation.

So I guess as a matter of fact, the increasing droughts or flooding we are told are occurring due to Climate Change, may be caused more or less by volcanic activity rather than human activity. Among other possible agents.

[Rella]

https://news.climate.columbia.edu/2021/03/09/volcano-impacts-global-precipitation/

Interesting quoted article below, from link above. About volcano eruptions and climate effects or change.

So I guess as a matter of fact, the increasing droughts or flooding we are told are occurring due to Climate Change, may be caused more or less by volcanic activity rather than human activity. Among other possible agents.

IOW...God!

[Wycliffes_Shillelagh]

Volcanos cause short-term global cooling and acid rain.  But we haven't had any major eruptions since... the Dark Ages?

[Amo]

https://www.smithsonianmag.com/science-nature/sixth-century-misery-tied-not-one-two-volcanic-eruptions-180955858/

Quoted article below from link above. Emphasis is mine.

Sixth-Century Misery Tied to Not One, But Two, Volcanic Eruptions

The ancient event is just one among hundreds of times volcanoes have affected climate over the past 2,500 years

In the summer of A.D. 536, a mysterious cloud appeared over the Mediterranean basin. "The sun gave forth its light without brightness," wrote the Byzantine historian Procopius, "and it seemed exceedingly like the sun in eclipse, for the beams it shed were not clear." In the wake of the cloud's appearance, local climate cooled for more than a decade. Crops failed, and there was widespread famine. From 541 to 542, a pandemic known as the Plague of Justinian swept through the Eastern Roman Empire.

Scientists had long suspected that the cause of all this misery might be a volcanic eruption, probably from Ilopango in El Salvador, which filled Earth's atmosphere with ash. But now researchers say there were two eruptions—one in 535 or 536 in the northern hemisphere and another in 539 or 540 in the tropics—that kept temperatures in the north cool until 550.

The revelation comes from a new analysis that combines ice cores collected in Antarctica and Greenland with data from tree rings. It shows that the sixth-century tragedy is just one chapter in a long history of volcanic interference. According to the data, nearly all extreme summer cooling events in the northern hemisphere in the past 2,500 years can be traced to volcanoes.

When a volcano erupts, it spews sulfur particles called aerosols into the air, where they can persist for two to three years. These aerosols block out some of the sun's incoming radiation, causing cooling. How much light gets blocked and how long the effect lasts depends on the location of the volcano and the magnitude of the eruption, as well as other variables in Earth's natural climate-control system.

Trees record the climate impacts of an eruption in the size of their rings—when a climate-related event occurs, the rings may appear wider or thinner than average, depending on whether the region is typically wet or dry and the normal length of the growing season. Meanwhile, the sulfur particles eventually fall to Earth and get incorporated into polar and glacial ice, providing a record of the eruptions.

Combining the two types of records, though, has proven difficult in the past. So Michael Sigl of the Desert Research Institute and his colleagues used more ice cores than any previous study. They also employed a method to enhance the resolution in the data obtained from the cores: melting the core from one end and continuously analyzing the meltwater. The team then used a sophisticated algorithm to match up their ice core data with existing tree ring datasets.

The researchers detected 238 eruptions from the past 2,500 years, they report today in Nature. About half were in the mid- to high-latitudes in the northern hemisphere, while 81 were in the tropics. (Because of the rotation of the Earth, material from tropical volcanoes ends up in both Greenland and Antarctica, while material from northern volcanoes tends to stay in the north.) The exact sources of most of the eruptions are as yet unknown, but the team was able to match their effects on climate to the tree ring records.

The analysis not only reinforces evidence that volcanoes can have long-lasting global effects, but it also fleshes out historical accounts, including what happened in the sixth-century Roman Empire. The first eruption, in late 535 or early 536, injected large amounts of sulfate and ash into the atmosphere. According to historical accounts, the atmosphere had dimmed by March 536, and it stayed that way for another 18 months.

Tree rings, and people of the time, recorded cold temperatures in North America, Asia and Europe, where summer temperatures dropped by 2.9 to 4.5 degrees Fahrenheit below the average of the previous 30 years. Then, in 539 or 540, another volcano erupted. It spewed 10 percent more aerosols into the atmosphere than the huge eruption of Tambora in Indonesia in 1815, which caused the infamous "year without a summer". More misery ensued, including the famines and pandemics. The same eruptions may have even contributed to a decline in the Maya empire, the authors say.

"We were amazed at the close correspondence and the consistency of the climate response to volcanic sulfate forcing during the entire 2,500-year period," says coauthor Joe McConnell of the Desert Research Institute. "This clearly shows the marked impact that volcanic eruptions have on our climate and, in some cases, on human health, economics and so history."

From the above and opening article, it seems to me that the world might focus more upon the higher chances of global cooling than global warming. From highly increased volcanic activity, or major eruptions at any given time, which apparently bring about more rapid and immediate effects.

[Wycliffes_Shillelagh]

From the above and opening article, it seems to me that the world might focus more upon the higher chances of global cooling than global warming. From highly increased volcanic activity, or major eruptions at any given time, which apparently bring about more rapid and immediate effects.

It's tough to predict super-volcanic eruptions, when they are so infrequent.

Thera erupted in ~1500BC, there were the one/two in the 600s in South America.  I believe there was one during the dark ages (~1300) in SE Asia.  Krakatoa erupted at the end of the 19th century, but only affected weather for about a year.  None of them will likely erupt again for thousands of years.

Taal Lake in the Philippines is a candidate.  It had a minor eruption last year.  And there's always Yellowstone, but if that one erupts the weather change will be the least of our worries here in the Americas.

[Amo]

If Yellowstone blows wide open, this nation would likely be part of history books alone. If as the article suggests though, that climate has been effected hundreds times over the last 2500 years by volcanic activity, I see no reason to discount this factor among the changes claimed for today. Volcanos are erupting somewhere on the planet all the time, I do believe. No doubt with far more local effect than global.

Still, the Climate Changers do focus in on localized weather events the globe over, to support their theory of human global effect. It might be good to look at volcanic activity in relation to these events, and or other possible agents of change, before simply attributing numerous localized events on the global scale to human activity alone.