#California; #IslandBuilding; #GreenlandIceSheet; #SouthEastAsia
California (US), Sep 24 (Canadian-Media): The Greenland ice sheet owes its existence to the growth of an arc of islands in Southeast Asia—stretching from Sumatra to New Guinea—over the last 15 million years, a new study claims, phys.org/news reports said.
Mt. Sumbing, an arc volcano in Central Java, in 2016. The uplift of volcanic rock in the entire Southeast Asian island arc, starting 15 million years ago, triggered global cooling and eventually ice sheets that covered much of North America and Northern Europe 18,000 years ago, according to UC Berkeley scientists and their colleagues. Credit: UC Berkeley photo by Yuem Park
According to an analysis by researchers at the University of California, Berkeley, UC Santa Barbara and a research institute in Toulouse, France, as the Australian continent pushed these volcanic islands out of the ocean, the rocks were exposed to rain mixed with carbon dioxide, which is acidic. Minerals within the rocks dissolved and washed with the carbon into the ocean, consuming enough carbon dioxide to cool the planet and allow for large ice sheets to form over North America and Northern Europe.
"You have the continental crust of Australia bulldozing into these volcanic islands, giving you really high mountains just south of the equator," said Nicholas Swanson-Hysell, associate professor of earth and planetary science at UC Berkeley and senior author of the study. "So, you have this big increase of land area that is quite steep, in a region where it's warm and wet and a lot of rock types that have the ability to naturally sequester carbon."
Starting about 15 million years ago, this tropical mountain-building drew down carbon dioxide in the atmosphere, decreasing the strength of the greenhouse effect and cooling the planet. By about 3 million years ago, Earth's temperature was cool enough to allow snow and ice to remain through the summer and grow into huge ice sheets over the Northern Hemisphere, like that covering Greenland today.
Once Northern Hemisphere ice sheets grew, other climate dynamics led to a cycle of glacial maxima and minima every 40,000 to 100,000 years. At the most recent glacial maximum, about 15,000 years ago, massive ice sheets covered most of Canada, the northern portions of the U.S., as well as Scandinavia and much of the British Isles.
"If it wasn't for the carbon sequestration that's happening in the Southeast Asian islands, we wouldn't have ended up with the climate that includes a Greenland ice sheet and these glacial and interglacial cycles," Swanson-Hysell said. "We wouldn't have crossed this atmospheric CO2 threshold to initiate Northern Hemisphere ice sheets."
The periodic growth and decline of the northern ice sheets—the cycle of glacial maxima and minima—is likely postponed, due to human emissions that have increased carbon dioxide concentrations in the atmosphere.
"A process that took millions of years we have reversed in 100 years," Swanson-Hysell said. "Over the next tens to hundreds of thousands of years, geological processes in places like Southeast Asia will once again decrease CO2 levels in the atmosphere—a pace that is frustratingly slow when humanity is facing the impact of current global warming."
UC Berkeley doctoral student Yuem Park, Swanson-Hysell and their colleagues, including Francis Macdonald of UC Santa Barbara and Yves Goddéris of Géosciences Environnement Toulouse, will publish their findings this week in the journal Proceedings of the National Academy of Sciences.
Geologists have long speculated about the processes that periodically warm and cool the planet, occasionally covering the entire globe with ice and turning it into a so-called snowball Earth.
Once scientists realized that, over the course of millions of years, tectonic processes move land masses around the planet like massive jigsaw puzzle pieces, they sought a connection between continental movements—and collisions—and ice ages. Cycles of Earth's orbit are responsible for the 40,000- or 100,000-year fluctuations in temperature that overlay the long-term warming and cooling.
The rise of the Himalayas in Asia in the mid-latitudes over the past 50 million years has been a prime candidate for cooling and the start of a glacial climate after an extended geologic interval without ice sheets. A few years ago, however, Swanson-Hysell and Macdonald saw a correlation between mountain-building in tropical areas and the onset of time intervals with ice ages over the past 500 million years.
In 2017, they proposed that a major ice age 445 million years ago was triggered by mountain- building in the tropics, and they followed that in 2019 with a more complete correlation of the last four time intervals of glacial climate and collisions between continents and tropical island arcs. They argue that the combination of increased exposure of rock with minerals that can sequester carbon and a plenitude of warm tropical rain is particularly effective in pulling carbon dioxide from the atmosphere.
The process involves chemical dissolution of the rocks that consume carbon dioxide, which is then locked in carbonate minerals that form limestone rock in the ocean. The calcium within seashells that you find on the beach may have come out of a tropical mountain on the other side of the world, Swanson-Hysell said.
"We built up a new database of these types of mountain-building events and then reconstructed the latitude at which they happened," Swanson-Hysell said. "Then we saw, hey, there is a lot of cooling when there is a lot of this type of mountain being built in the tropics, which is the Southeast Asian setting. The Southeast Asian islands are the best analog for processes that we also see further in the past."
For the current paper, Park, Swanson-Hysell and Macdonald teamed up with Goddéris to model more precisely what carbon dioxide levels would be with changes in the size of the Southeast Asian islands.
The researchers first recreated the sizes of the islands as they grew over the last 15 million years, focusing primarily on the largest: Java, Sumatra, the Philippines, Sulawesi and New Guinea. They calculated that the area of the islands increased from 0.3 million square kilometers 15 million years ago to 2 million square kilometers today. UC Santa Barbara graduate student Eliel Anttila, who was an undergraduate student in earth and planetary science at UC Berkeley and is a co-author of the paper, contributed to this aspect of the research.
They then used Godderis' GEOCLIM computer model to estimate how the growth of these islands altered carbon levels in the atmosphere. Together with UC Berkeley postdoctoral scholar Pierre Maffre, who recently obtained his Ph.D. in Godderis' lab, they updated the model to account for the variable effect of different rock types. The model is linked with a climate model in order to relate CO2 levels to global temperatures and precipitation.
They found that the increase of land area along the southeast edge of the Pacific corresponded with global cooling, as reconstructed from oxygen isotope compositions in ocean sediments. The carbon dioxide levels inferred from the model also match some measurement-based estimates, though Swanson-Hysell admits that estimating CO2 levels more than a million years ago is difficult and uncertain.
Based on their model, chemical weathering in the Southeast Asian islands alone diminished CO2 levels from more than 500 parts per million (ppm) 15 million years ago to approximately 400 ppm 5 million years ago and, finally, to pre-industrial levels of 280 ppm. Fossil fuel-burning has now raised the level of carbon dioxide in the atmosphere to 411 ppm—levels that haven't been seen on Earth for millions of years.
While the threshold for Arctic glaciation is estimated to be about 280 ppm of carbon dioxide, the threshold for ice sheet formation at the South Pole is much higher: about 750 ppm. That's why the Antarctic ice sheets began forming much earlier, about 34 million years ago, than those in the Arctic.
While the researchers' model doesn't allow them to isolate the climatic effects of the rise of the Himalayas, their Southeast Asian island scenario alone can account for the appearance of Northern Hemisphere ice sheets. They did explore the effect of volcanic events occurring around the same time, including massive lava flows, or flood basalts, such as those in Ethiopia and North America (Columbian traps). Though the weathering of such rocks has been proposed as an ice age trigger, the model shows that this activity played a minor role, compared to the rise of the Southeast Asian islands.
"These results highlight that the Earth's climate state is particularly sensitive to changes in tropical geography," the authors conclude.
Swanson-Hysell credits the campus's France-Berkeley Fund for providing resources for an initial collaboration with Goddéris that led to a large collaborative grant from the National Science Foundation's (NSF's) Frontier Research in Earth Science program to further pursue the research resulting in this paper.
The French-American team plans to model other past ice ages, including the one in the Ordovician period 445 million years ago that, in 2017, Swanson-Hysell and Macdonald proposed was triggered by a collision similar to that occurring today in the Southeast Asian islands. That collision took place during the first phase of Appalachian mountain-building, when the present-day eastern U.S. was located in the tropics.
#Bangkok, #FAO; #Covid19; #UN; #UNSDGs; #SDGs;
Bangkok, Sep 6 (Canadian-Media): Innovation, solidarity, coherence and strong partnership among and within countries of Asia and the Pacific are required for the region to rebound from the damage caused by COVID-19 and the ongoing effects of chronic undernourishment, FAO reports said.
Drones used in the Philippines to assess damages to agricultural land caused by severe weather events. Image credit: FAO
That was a call made by more than 40 member countries of the Food and Agriculture Organization of the United Nations concluding a four-day regional conference. About 750 participants, including representatives of the private sector and civil society, pledged to work to transform food systems, making them more sustainable, productive and resilient, and to feed a hungry world in a way that is profitable for farmers yet produces healthy food that is accessible to all.
"To transform food systems for sustainable healthy diets we must have coherence, partnerships and solidarity to reduce the costs of production," FAO Director-General QU Dongyu said on the final day of the 35th Regional Conference for Asia and the Pacific, hosted by the Government of Bhutan.
"Big data, a digital economy and mobile technology will help producers achieve that." Today, mobile technology is leading innovation "and a smartphone in the hands of a smallholder farmer is his new farming tool," the Director-General added.
The Conference also learned more about the establishment of a FAO Office of Innovation and the creation of an International Platform for Digital Food and Agriculture.
The Conference heard that agricultural innovation can reduce back-breaking drudgery, and that food chains in the Asia-Pacific region are increasingly benefitting from technological innovation such as drones, satellite imagery, big data and block chains.
"Leveraging data, innovation and technology has shown that, here in Asia and the Pacific, we have brilliant minds, scientists and an entrepreneurial spirit that will lead us through the challenges presented by COVID-19 and help us conquer malnutrition and poverty," the Director-General said.
The Conference held a special session dedicated to the application of new technology and innovation in agriculture, which are wooing back young people and empowering women in the sector, according to participants. It was agreed that new and innovative food and agricultural policies, processes, investment and learning could get the region back on track to achieve Sustainable Development Goal 2 (ending hunger and promoting sustainable agriculture) by 2030.COVID-19 underscores the need to redouble efforts to end hunger and poverty.
The Asia-Pacific region is home to more than half of the world's undernourished people, and with the impacts of COVID-19 the number of hungry people in Southern Asia could rise by nearly a third to 330 million in the next ten years.
The participants heard how FAO's recently launched COVID-19 Response and Recovery Programme, would help countries mitigate the immediate impacts of the pandemic while build back better, accelerating global hunger-fighting efforts through a focus on innovation.
The Conference was chaired by the Minister for Agriculture and Forests of Bhutan, Yeshey Penjor, who called for strengthened collaboration: "While great strides had been made to reduce poverty and hunger by so many countries, COVID-19 has upended the momentum. We must prepare for higher risks ahead of us and make sure that there is sustainability in the food supply chain," he said.
The Conference also appreciated the FAO Hand in Hand Initiative that aims to enable matchmaking, bringing the right partners together at the right time, to help the region move forward and meet the needs of member countries. The Initiative has already seen the launch of state-of-the-art tools such as the Hand-in-Hand Geospatial Platform and the FAO Data Lab for statistical innovation.
"Ironically, the fact that COVID-19 has driven us to meet remotely has, in some ways, helped us to move away from formalities and get closer together," said Director-General QU, referring to the fact the Regional Conference was held entirely in virtual mode for the first time in FAO's history. "So while we are separated by some 11 time zones, we have still managed to come together, have thought-provoking discussions and reach consensus on a number of important issues."
There were a number of other firsts and achievements. The private sector joined for the first time a FAO Asia and the Pacific Regional Conference. Civil society organizations also continued to have an important voice. Prior to the conference, which is part of FAO's regional governance structure, national consultations were held in member nations across the region - another first.
#Northern England; #Archaeology; #LeadChristianCupUncovered; #Christianity
England, Sep 3 (Canadian-Media): Archaeologists have uncovered the fragments of a lead Christian cup, or chalice, lightly etched with symbols of early Christian iconography, at the archaeological site of Vindolanda, an ancient Roman military fort and settlement on Hadrian’s Wall in Northumberland, northern England, www.sci-news.com reports said.
A fragment of the 1,400-year-old Christian chalice found at Vindolanda in Northumberland, northern England. Image credit: Vindolanda Trust.
A total of 14 fragments from the ancient vessel were found hidden in the remains of a 6th century Christian church, inside the previously occupied Roman fort of Vindolanda.
“This is a really exciting find from a poorly understood period in the history of Britain,” said lead author Dr. David Petts, a researcher in the Department of Archaeology at Durham University.
“Its apparent connections with the early Christian church are incredibly important, and this curious vessel is unique in a British context.”
“It is clear that further work on this discovery will tell us much about the development of early Christianity in beginning of the medieval period.”
Each fragment of the ancient chalice was found to be covered by lightly etched symbols, each representing different forms of Christian iconography from the time.
The marks appear to have been added, both to the outside and the inside of this cup, by the same hand or artist and although they are now difficult to see with the naked eye, with the aid of specialist photography, the symbols have been carefully recorded and work has started on a new journey of discovery to unlock their meanings.
The etchings include some well-known symbols from the early church including ships, crosses and chi-rho, fish, a whale, a happy bishop, angels, members of a congregation, letters in Latin, Greek and potentially Ogam.
“We are used to first’s and the wow factor from our impressive Roman remains at Vindolanda with artifacts such as the ink tablets, boxing gloves, boots and shoes, but to have an object like the chalice survive into the post-Roman landscape is just as significant,” said Dr. Andrew Birley, director of excavations and CEO of the Vindolanda Trust.
“Its discovery helps us appreciate how the site of Vindolanda and its community survived beyond the fall of Rome and yet remained connected to a spiritual successor in the form of Christianity which in many ways was just as wide reaching and transformative as what had come before it.”
“I am delighted that we can now start to share our news about this discovery and shed some light on an often-overlooked period of our heritage and past.”
#Greenland; #MassiveIceSheetsheds; #SeaLevelRise
Greenland, Aug 23 (Canadian-Media): Greenland's massive ice sheet saw a record net loss of 532 billion tonnes last year, raising red flags about accelerating sea level rise, according to new findings, https://phys.org/news/2020 news reports said.
Until 2000, Greenland's ice sheet accumulated as much mass as it shed
That is equivalent to an additional three million tonnes of water streaming into global oceans every day, or six Olympic pools every second.
Crumbling glaciers and torrents of melt-water slicing through Greenland's ice block—as thick as ten Eiffel Towers end-to-end—were the single biggest source of global sea level rise in 2019 and accounted for 40 percent of the total, researchers reported in the journal Communications Earth & Environment.
Last year's loss of mass was at least 15 percent above the previous record in 2012, but even more alarming are the long-term trends, they said.
"2019 and the four other record-loss years have all occurred in the last decade," lead author Ingo Sasgen, a glaciologist at the Helmholtze Centre for Polar and Marine Research in Germany, told AFP.
The ice sheet is now tracking the worst-case global warming scenario of the UN's climate science advisory panel, the IPCC, noted Andrew Shepherd, director of the Centre for Polar Observation and Modelling at the University of Leeds.
"This means we need to prepare for an extra ten centimetres or so of global sea level rise by 2100 from Greenland alone," said Shepherd, who was not involved in the study.
Redraw world's coastlines
If all of Greenland's ice sheet were to melt, it would lift global oceans by seven metres (23 feet).
Even a more modest rise of a couple of metres would redraw the world's coastlines and render land occupied today by hundreds of millions of people uninhabitable.
ntil 2000, Greenland's ice sheet—covering an area three times the size of France—generally accumulated as much mass as it shed.
Runoff, in other words, was compensated by fresh snowfall.
But over the last two decades ago, the gathering pace of global warming has upended this balance.
The gap is widening at both ends, according to the study, which draws from nearly 20 years of satellite data.
Changing weather patterns—also a consequence of climate change—has resulted in less cloud cover, and thus less snow. These high pressure systems have also resulted in more, and warmer, sunny days, accelerating the loss of mass.
In 2019, the ice sheet lost a total of 1.13 trillion tonnes, about 45 percent from glaciers sliding into the sea, and 55 percent from melted ice, said Sasgen. It gained about 600 billion tonnes through precipitation.
A study in the same journal last week concluded that the Greenland's ice sheet has passed a "tipping point", and is now doomed to disintegrate, though on what time scale is unknown.
'Alarm bells ringing'
Sasgen says it is too soon to know if we have reached a point of no return, but agrees that the ice sheet is likely to continue losing mass, even in colder years.
"But that doesn't mean that trying to limit warming doesn't matter," he added.
"Every decimal degree you save in terms of warming will save a certain amount of sea level rise, both in magnitude and speed."
At the other end of the world, the West Antarctic Ice Sheet—which holds another six metres worth of sea level rise—is similarly thought to be teetering on a tipping point, with many experts convinced it has already passed it.
Scientists not involved in the research were not surprised by the findings, but expressed concern.
"The ice sheet has lost ice every year for the last 20 years," said Twila Moon, a research scientists at the University of Colorado.
"If everyone's alarm bells were not already ringing, they must be now."
Stuart Cunningham, an oceanographer from the Scottish Association for Marine Science, warned about the potential impact on the North Atlantic circulation, a current that keeps northwestern Europe five to ten degrees Celsius warmer that similar latitudes elsewhere on the globe.
"Climate models show this circulation can be switched off by adding fresh water to the North Atlantic," he said, noting this happened during the end of the last ice age.
"This tipping point in the climate system is one of the potential disasters facing us."
From 1992 to 2018, Greenland lost about four trillion tonnes of mass, causing the mean sea level to rise by 11 millimetres, according to a December 2019 study in Nature.
#Genomes; #Rhinos; #Extinction; #climateChange
The extinction of prehistoric megafauna like the woolly mammoth, cave lion, and woolly rhinoceros at the end of the last ice age has often been attributed to the spread of early humans across the globe, https://phys.org/news reports said.
This image shows the preserved, reconstructed remains of a baby woolly rhinoceros named Sasha that was discovered in Siberia. Image Credit: Albert Protopopov
Although overhunting led to the demise of some species, a study appearing August 13 in the journal Current Biology found that the extinction of the woolly rhinoceros may have had a different cause: climate change. By sequencing ancient DNA from 14 of these megaherbivores, researchers found that the woolly rhinoceros population remained stable and diverse until only a few thousand years before it disappeared from Siberia, when temperatures likely rose too high for the cold-adapted species.
"It was initially thought that humans appeared in northeastern Siberia fourteen or fifteen thousand years ago, around when the woolly rhinoceros went extinct. But recently, there have been several discoveries of much older human occupation sites, the most famous of which is around thirty thousand years old," says senior author Love Dalén, a professor of evolutionary genetics at the Centre for Palaeogenetics, a joint venture between Stockholm University and the Swedish Museum of Natural History. "So, the decline towards extinction of the woolly rhinoceros doesn't coincide so much with the first appearance of humans in the region. If anything, we actually see something looking a bit like an increase in population size during this period."
To learn about the size and stability of the woolly rhinoceros population in Siberia, the researchers studied the DNA from tissue, bone, and hair samples of 14 individuals. "We sequenced a complete nuclear genome to look back in time and estimate population sizes, and we also sequenced fourteen mitochondrial genomes to estimate the female effective population sizes," says co-first author Edana Lord, a Ph.D. student at the Centre for Palaeogenetics.
By looking at the heterozygosity, or genetic diversity, of these genomes, the researchers were able to estimate the woolly rhino populations for tens of thousands of years before their extinction.
"We examined changes in population size and estimated inbreeding," says co-first author Nicolas Dussex, a postdoctoral researcher at the Centre for Palaeogenetics. "We found that after an increase in population size at the start of a cold period some 29,000 years ago, the woolly rhino population size remained constant and that at this time, inbreeding was low."
This stability lasted until well after humans began living in Siberia, contrasting the declines that would be expected if the woolly rhinos went extinct due to hunting. "That's the interesting thing," says Lord. "We actually don't see a decrease in population size after 29,000 years ago. The data we looked at only goes up to 18,500 years ago, which is approximately 4,500 years before their extinction, so it implies that they declined sometime in that gap."
The DNA data also revealed genetic mutations that helped the woolly rhinoceros adapt to colder weather. One of these mutations, a type of receptor in the skin for sensing warm and cold temperatures, has also been found in woolly mammoths. Adaptations like this suggest the woolly rhinoceros, which was particularly suited to the frigid northeast Siberian climate, may have declined due to the heat of a brief warming period, known as the Bølling-Allerød interstadial, that coincided with their extinction towards the end of the last ice age.
"We're coming away from the idea of humans taking over everything as soon as they come into an environment, and instead elucidating the role of climate in megafaunal extinctions," says Lord. "Although we can't rule out human involvement, we suggest that the woolly rhinoceros' extinction was more likely related to climate."
The researchers hope to study the DNA of additional woolly rhinoceroses that lived in that crucial 4,500-year gap between the last genome they sequenced and their extinction.
"What we want to do now is to try to get more genome sequences from rhinos that are between eighteen and fourteen thousand years old, because at some point, surely they must decline," says Dalén. The researchers are also looking at other cold-adapted megafauna to see what further effects the warming, unstable climate had. "We know the climate changed a lot, but the question is: how much were different animals affected, and what do they have in common?"
#Norway; #Archaeology; #VikingTradeCenter
Tromsø (Norway), Jul 18 (Canadian-Media): According to a statement released by the Arctic University of Norway, archaeology student Tor-Kjetil Krokmyrdal has discovered a Viking trade center in northern Norway on the coast of the island of Hinnøya, www.archaeology.org/news reports said.
Norway Viking Imports. Image credit: Julie Holme Damman, The Arctic University Museum of Norway and Tor-Ketil Krokmyrdal.
Jewelry, weights, coins, and items related to forging iron and shipbuilding and repair have been recovered. The ninth-century site is the first of its kind to be found in the region.
Krokmyrdal said he began searching the site with a metal detector because the village where the site is located is named “Sandtorg,” which translates to “market or trading place at Sand.”
Tjelsund, the name of the local municipality, is related to the word “tjelde,” which means to spend a night in or under a boat resting on land. Krokmyrdal thinks a ninth-century chieftain living at the site may have controlled shipping through the straits separating the island from the mainland.
“The location is also very strategic in terms of trade,” Krokmyrdal said. “The current at Sandtorg is really strong, and all the travelers would have to wait until the current turned before they could continue their journey," he explained. To read about a Viking ship burial recently excavated on the Norwegian island of Edoya, go to "Sailing the Viking Seas."
#Archaeology; #OregonPaisleyCaves; #humanSterols
Newcastle Upon Tyne (England), Jul 18 (Canadian-Media): Gizmodo reports that archaeologists John Blong and Lisa-Marie Shillito of Newcastle University and their colleagues tested 21 coprolites unearthed in Oregon’s Paisley Caves for the presence of human sterols and bile, which are not soluble in water and thus chemically stable, https://www.archaeology.org news reports said.human sterols
Oregon-Paisley-Caves. Image credit: John Blong
Previous mitochondrial DNA testing of the ancient waste indicated that all of the samples were human in origin, but critics argued that DNA from later occupation of the cave may have washed into lower, older cave sediments and contaminated the samples. “We address issues of potential DNA contamination through fecal lipid biomarker analysis, providing evidence that there likely was DNA moving from younger human occupations into older cave sediments and coprolites, but also confirming that people were camping at the caves as early as 14,200 years ago,” Blong said. In the new analysis, only 13 of the 21 samples were identified as human droppings, while one was linked to a panther and another to a lynx. The researchers are now analyzing the coprolites for clues to what those early campers had eaten. For more on Paisley Caves, go to "America, in the Beginning."
Thanks to the extremely dry environment inside Oregon’s Paisley Caves, University of Oregon archaeologist Dennis Jenkins and his team came across five human droppings that dated to older than 14,000 years over the course of nine years of digging there.
In addition, they also found three points that Jenkins believes belong to what is known as the Western Stemmed tradition. Unlike Clovis points, which have a signature notch at their base so that wooden spears can be attached, these have constricted bases. They have also clearly been struck from smaller pieces of stone than the typical Clovis counterpart. Two human coprolites dated to just over 13,000 years ago were found within eight inches of one of the points. At the very least, this evidence suggests that there was a parallel occupation of the continental United States by both the Clovis people and a second group who made different types of tools.
Evidence of baskets and rope, plant fibers, wooden artifacts, and animal bones were also found at the caves. Pollen and other plant minerals extracted from the coprolites suggest that people came to the site in the spring and early summer. They also provide evidence that the people in the caves ate everything from edible roots to bison, horse, and even animals as big as mastodon.
Jenkins, for his part, thinks Paisley Caves were not a destination location. “There is very little debitage [residue from production] from stone tools over time,” he explains. “The archaeology suggests this is a place where people are passing by—something, weather or resources nearby, or the time of day, makes you stop in.”
#EarthSciences; #OriginOfWaterOnEarth; #NASA
Hokkaido University (Japan), Jul 18 (Canadian-Media): According to a current study published in Scientific Reports, scientists have found the interstellar organic matter could produce an abundant supply of water by heating, suggesting that organic matter could be the source of terrestrial water.
Organic matter in nebula could be the source of terrestrial water. Image Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)
There remains a number of mysteries on our planet including the elusive origin of water on the earth. Active studies suggested that terrestrial water had been delivered by icy comets or meteorites containing hydrous silicates that came from outside the "snow line"—the boundary beyond which ice can condense due the low temperatures. More recent studies, however, have provided observations opposing to cometary origin theory, yet still failing to suggest plausible substitutions for the source of terrestrial water. "Until now, much less attention has been paid to organic matter, comparing to ices and silicates, even though there is an abundance inside the snow line" says planetary scientist Akira Kouchi at Hokkaido University.
In the current study published in Scientific Reports, a group of scientists led by Akira Kouchi demonstrates that heating of the interstellar organic matter at high temperature could yield abundant water and oil. This suggests that water could be produced inside the snow line, without any contribution of comets or meteorites delivered from outside the snow line.
New insight into the origin of water on the earth
As a first step, the researchers made an analog of organic matter in interstellar molecular clouds using chemical reagents. To make the analog, they referred to analytical data of interstellar organics made by irradiating UV on a mixture containing H2O, CO, and NH3, which mimicked its natural synthetic process. Then, they gradually heated the organic matter analog from 24 to 400 ℃ under a pressured condition in a diamond anvil cell. The sample was uniform until 100 ℃, but was separated into two phases at 200 ℃. At approximately 350 ℃, the formation of water droplets became evident and the sizes of the droplets increased as the temperature rose. At 400 ℃, in addition to water droplets, black oil was produced.
The group conducted similar experiments with larger amounts of organic matter, which also yielded water and oil. Their analysis of absorption spectra revealed that the main component of the aqueous product was pure water. Additionally, chemical analysis of produced oil showed similar characteristics to the typical crude oil found beneath the earth.
Organic matter analog producing water and oil by heating. Round water droplets were remarkably formed at approximately 350 ℃. Credit: Hideyuki Nakano et al., Scientific Reports"Our results show that the interstellar organic matter inside the snow line is a potential source of water on the earth. Moreover, the abiotic oil formation we observed suggests more extensive sources of petroleum for the ancient Earth than previously thought," says Akira Kouchi. "Future analyses of organic matter in samples from the asteroid Ryugu, which the Japan's asteroid explorer Hayabusa2 will bring back later this year, should advance our understanding of the origin of terrestrial water."
#EarthSciences; #Forests; #GreenhouseGasEmissions; #ClimateInvestment
Utah (US), Jun 18 (Canadian-Media): Given the tremendous ability of forests to absorb carbon dioxide from the atmosphere, some governments are counting on planted forests as offsets for greenhouse gas emissions—a sort of climate investment, phys.org/news/2020 reports said.
But as with any investment, it's important to understand the risks. If a forest goes bust, researchers say, much of that stored carbon could go up in smoke.
In a paper published in Science, University of Utah biologist William Anderegg and his colleagues say that forests can be best deployed in the fight against climate change with a proper understanding of the risks to that forest that climate change itself imposes. "As long as this is done wisely and based on the best available science, that's fantastic," Anderegg says. "But there hasn't been adequate attention to the risks of climate change to forests right now."
Increasing climate-driven disturbance risk over time has major impacts on forest carbon. Conceptual diagram of stationary/constant (top) versus non-stationary/increasing (bottom) permanence risks from disturbance at a landscape scale in a changing climate. Disturbance risks are illustrated via circles and include fire, drought, biotic agents, and human disturbance. Image credit: David Meikle.
Meeting of minds
In 2019, Anderegg, a recipient of the Packard Fellowship for Science and Engineering from the David and Lucile Packard Foundation, convened a workshop in Salt Lake City to gather some of the foremost experts on climate change risks to forests. The diverse group represented various disciplines: law, economics, science and public policy, among others. "This was designed to bring some of the people who had thought about this the most together and to start talking and come up with a roadmap," Anderegg says.
This paper, part of that roadmap, calls attention to the risks forests face from myriad consequences of rising global temperatures, including fire, drought, insect damage and human disturbance—a call to action, Anderegg says, to bridge the divide between the data and models produced by scientists and the actions taken by policymakers.
Forests absorb a significant amount of the carbon dioxide that's emitted into the atmosphere—just under a third, Anderegg says. "And this sponge for CO2 is incredibly valuable to us."
Because of this, governments in many countries are looking to "forest-based natural climate solutions" that include preventing deforestation, managing natural forests and reforesting. Forests could be some of the more cost-effective climate mitigation strategies, with co-benefits for biodiversity, conservation and local communities.
But built into this strategy is the idea that forests are able to store carbon relatively "permanently", or on the time scales of 50 to 100 years—or longer. Such permanence is not always a given. "There's a very real chance that many of those forest projects could go up in flames or to bugs or drought stress or hurricanes in the coming decades," Anderegg says.
Forests have long been vulnerable to all of those factors, and have been able to recover from them when they are episodic or come one at a time. But the risks connected with climate change, including drought and fire, increase over time. Multiple threats at once, or insufficient time for forests to recover from those threats, can kill the trees, release the carbon, and undermine the entire premise of forest-based natural climate solutions.
"Without good science to tell us what those risks are," Anderegg says, "we're flying blind and not making the best policy decisions."
In the paper, Anderegg and his colleagues encourage scientists to focus increased attention on assessing forest climate risks and share the best of their data and predictive models with policymakers so that climate strategies including forests can have the best long-term impact. For example, he says, the climate risk computer models scientists use are detailed and cutting-edge, but aren't widely used outside the scientific community. So, policy decisions can rely on science that may be decades old.
"There are at least two key things you can do with this information," Anderegg says. The first is to optimize investment in forests and minimize risks. "Science can guide and inform where we ought to be investing to achieve different climate aims and avoid risks."
The second, he says, is to mitigate risks through forest management. "If we're worried about fire as a major risk in a certain area, we can start to think about what are the management tools that make a forest more resilient to that disturbance." More research, he says, is needed in this field, and he and his colleagues plan to work toward answering those questions.
"We view this paper as an urgent call to both policymakers and the scientific community," Anderegg says, "to study this more, and improve in sharing tools and information across different groups."
Ottawa, May 29 (Canadian-Media): Seamus O’Regan, Canada’s Minister of Natural Resources, participated May 29 in the International Energy Agency’s (IEA) second in a series of ministerial roundtables that will result in the Clean Energy Transitions Summit taking place on July 9, media reports said.
Throughout the crisis of COVID-19 pandemic outbreak around the world, Canada's energy sector has been providing the power needed by Canadians and essential services and ensured the security and reliability of our electricity grid during the pandemic, including protecting against cyber threats.
Today’s roundtable hosted by IEA Executive Director Dr. Fatih Birol and Kwasi Kwarteng, Minister of State for Business, Energy and Clean Growth in the United Kingdom, focused on mobilizing investments for secure and sustainable power systems.
Canada’s crucial role in its increased electrification to achieve its climate change commitments under the Paris Agreement and its commitment to achieve net-zero emissions by 2050, was highlighted by Minister O’Regan.
He also highlighted Canada’s contribution to the North American energy system, importance of electricity systems to modern society, particularly in the context of the COVID-19 pandemic, measures needed to ensure secure and sustainable industry investments, and the future opportunities for international cooperation and collaboration were discussed by all participants.
During the roundtable, Minister O’Regan emphasized that Canada had ensured no continental electricity disruptions during the pandemic crisis.
Committed to building a clean energy future to support our natural resource sectors through this tough economic time, government of Canada also sees to the growth of its economy and create good jobs.
“COVID-19 has changed our world, but it hasn’t dampened our resolve. We will get through this. We will build economies that are stronger and more resilient than before. With collaboration between international partners at forums like the IEA, the clean energy transition that is already underway will play a critical role in the global economic recovery,” said O’Regan.