“It’s true that during the Little Ice Age it was generally colder across the whole world,” research team leader Raphael Neukom of the Oeschger Center for Climate Change Research at the University of Bern said, “but not everywhere at the same time. The peak periods of pre-industrial warm and cold periods occurred at different times in different places.” For example, the Little Ice Age was coldest in the Pacific in the 15th century, Europe in the 17th century and elsewhere in the 19th century, The Guardian reported.
The current climate crisis is unique in the last 2,000 years of history, a trio of papers has found, in that it is the only truly global climate shift during the last two millennia.
Previous anomalies like the Little Ice Age, when it was possible to skate on the Thames, were more regional in scope, while the warming trend at the end of the 20th century affected more than 98 percent of the planet, Reuters reported.
In contrast to pre-industrial #climate fluctuations, current, anthropogenic climate change is occurring across the whole world at the same time & is warming the planet faster than in the last 2,000 years: http://ow.ly/5wjD50vacxJ @CentreOeschger @nature @NatureGeosci @NatureNews
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“The main takeaway is that climate variability in the contemporary period is very different than what’s happened in the past 2,000 years,” Columbia University climate scientist Nathan Steiger, who co-authored one of the papers published in Nature Wednesday, told Reuters. “This is definitely further evidence that fossil fuels and anthropogenic activity actually has fundamentally changed the climate,” he added.
Some climate deniers have pointed to past climate shifts to argue that there is nothing new or human-caused about the current warming period. The Medieval Climate Anomaly warmed temperatures from 800 to 1200 AD and the Little Ice Age saw temperatures fall from the 1300s to the 1850s, but the new research shows that these and other events were much more localized than current climate change. None of them covered more than half the globe at any one time, according to The Guardian.
Nathan Steiger@njsteiger · Jul 24, 2019
Our paper out today in Nature: the death of the Little Ice Age and the Medieval Climate Anomaly, or at least the death of how you may have known them. https://www.nature.com/articles/s41586-019-1401-2 …No evidence for globally coherent warm and cold periods over the preinWarm and cold periods over the past 2,000 years have not occurred at the same time in all geographical locations, with the exception of the twentieth century, during which warming has occurred almost…nature.com
Based on 6 different probabilistic reconstruction methods using the PAGES2k proxy database, we show that Common Era climate epochs were not globally coherent phenomena. Warmth and cold happened in different places at different times.211:05 AM – Jul 24, 2019Twitter Ads info and privacySee Nathan Steiger’s other Tweets
In the past, researchers had taken evidence for these warming and cooling periods in Europe and North America and assumed they applied to the rest of the globe, the University of Bern explained in a press release. But for this week’s papers, researchers consulted the PAGES (Past Global Changes) database of worldwide climate data from tree rings, ice cores, lake sediments and corals.
“It’s true that during the Little Ice Age it was generally colder across the whole world,” research team leader Raphael Neukom of the Oeschger Center for Climate Change Research at the University of Bern said, “but not everywhere at the same time. The peak periods of pre-industrial warm and cold periods occurred at different times in different places.” For example, the Little Ice Age was coldest in the Pacific in the 15th century, Europe in the 17th century and elsewhere in the 19th century, The Guardian reported.
“This paper should finally stop climate change deniers claiming that the recent observed coherent global warming is part of a natural climate cycle. This paper shows the truly stark difference between regional and localised changes in climate of the past and the truly global effect of anthropogenic greenhouse emissions,” University College London climatology professor Mark Maslin told The Guardian.
The Nature paper was accompanied by a second, published in Nature Geoscience, that focused on the impacts of five large volcanic eruptions during the early 19th century that caused cooler temperatures, drought in Africa and the advance of glaciers in the Alps, the University of Bern further explained.
5 large volcanic eruptions in the early 19th century led to dry monsoon regions and growing glaciers in the Alps, according to a study led by the @CentreOeschger of the #unibern. http://ow.ly/Ws6j50vadhW #climate @NatureGeosci
1111:30 AM – Jul 24, 2019Twitter Ads info and privacySee Universität Bern’s other Tweets
Because these eruptions occurred at the start of the industrial revolution, researchers say it is difficult to determine how volcanism interacted with the increasing burning of greenhouse gasses to impact climate at that time.
“It does sort of mask the effect of industrial processes, where they are starting to omit more CO2, because they counteract each other,” Steiger told Smithsonian.com. “So volcanoes could cool, and humans would warm by the release of greenhouse gasses. It’s tricky to parse out what’s what.”
This matters because international targets like the Paris agreement seek to limit warming to certain amounts above a pre-industrial norm.
“Given the large climatic changes seen in the early 19th century, it is difficult to define a pre-industrial climate, a notion to which all our climate targets refer,” lead author and University of Bern climatologist Stefan Brönnimann said in the university release.
But what is clear is that today’s warming is unprecedented during the study period. A final paper, also published in Nature Geoscience, concluded that the rates of warming documented in the second half of the 20th century were the fastest in 2,000 years.
That finding “highlights the extraordinary character of current climate change,” Neukom told Smithsonian.com.RELATED ARTICLES AROUND THE WEB
- No Climate Event in 2000 Years Compares to What’s Happening Now ›
- Global warming dwarfs climate variations of past 2,000 years – study … ›
‘Unprecedented’ Wildfires in Arctic Have Scientists Concerned
Jordan Davidson Jul. 25, 2019 CLIMATE Satellite images show wildfires burning through the Central Siberian Plateau.
So many wildfires are burning in the Arctic, they’re visible from space, new images from NASA’s Earth Observatory show. The satellite images reveal huge plumes of smoke wafting across uninhabited lands in Siberia, Greenland and Alaska, as CNN reported.
Summer fires are common in the Arctic, but not at this scale.
“I think it’s fair to say July Arctic Circle #wildfires are now at unprecedented levels,” said Mark Parrington, a senior scientist at Europe’s Copernicus Atmosphere Monitoring Service, on Twitter earlier this week.
Copernicus’ scientists have been tracking more than 100 wildfires raging above the Arctic Circle since the start of June, which was the hottest June on record. July is on pace to break records too as Europe bakes under another heat wave this week.
“The magnitude is unprecedented in the 16-year satellite record,” said Thomas Smith, an assistant professor in environmental geography at the London School of Economics, to USA Today. “The fires appear to be further north than usual, and some appear to have ignited peat soils.”
Peat fires burn deeper in the ground and can last for weeks or even months instead of a few hours or days like most forest fires, according to the UPI.
The researchers at Copernicus track how much greenhouse gas the wildfires emit into the atmosphere as well. So far, the Arctic’s fires have released approximately 100 megatons, 100 million metric tons, of CO2 between June 1 and July 21, which Parrington said on Twitter “is getting close to 2017 fossil fuel CO2 emissions of Belgium” for the entire year, as USA Today reported.
Smith added another comparison to the amount of carbon released in the past two months.
“These are some of the biggest fires on the planet, with a few appearing to be larger than 100,000 hectares (380 square miles),” he told USA Today. “The amount of CO2 (carbon dioxide) emitted from Arctic Circle fires in June 2019 is larger than all of the CO2 released from Arctic Circle fires in the same month from 2010 through to 2018 put together.”
That number is likely to jump as the fires burn through the peat, which acts as a carbon reservoir.
“The fires are burning through long-term carbon stores (peat soil) emitting greenhouse gases, which will further exacerbate greenhouse warming, leading to more fires,” said Smith.
Parrington said that the Arctic is seeing temperatures rise twice as fast as the global average.
“What this means is that, following ignition, the environmental conditions have been ideal for the fires to grow and continue,” he told USA Today.
The fires were likely ignited by lightning strikes and are now enormous. The largest fires are located in Siberia, in the regions of Irkutsk, Krasnoyarsk and Buryatia, according to the Earth Observatory, as Live Science reported. They have conflagrations have burned 320 square miles, 150 square miles, and 41 square miles, respectively.
The #siberianfires in #KrasnoyarskKrai and #SakhaRepublic, #Russia now created a smoke lid extending over 4 and half million of sq km over central northern Asia. This is staggering. @m_parrington @CopernicusEU @DanLindsey77
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Atmospheric scientist Santiago Gasso said on Twitter the Siberian fires have “now created a smoke lid extending over 4 and half million (square km) over central northern Asia. This is staggering.”
Krasnoyarsk, the Russian city near the second largest fire, is blanketed in haze, according to the Earth Observatory. Siberia’s largest city, Novosibirsk, doesn’t have any fires as now, but smoke carried there by the winds caused the city’s air quality to drop, as Live Science reported. Right now, the city’s Air Quality Index is hazardous.
Since the fires in the Siberian arctic are raging in uninhabited areas, firefighters are not able to access them. Only rain will put them out.
Firefighters are working to put out the fires in Alaska since they are farther south, according to USA Today.
