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Permafrost thaw: a silent menace
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By NASA
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
The Permafrost Tunnel north of Fairbanks, Alaska, was dug in the 1960s and is run by the U.S. Army’s Cold Regions Research and Engineering Laboratory. It is the site of much research into permafrost — ground that stays frozen throughout the year, for multiple years.NASA/Kate Ramsayer Earth’s far northern reaches have locked carbon underground for millennia. New research paints a picture of a landscape in change.
A new study, co-authored by NASA scientists, details where and how greenhouse gases are escaping from the Earth’s vast northern permafrost region as the Arctic warms. The frozen soils encircling the Arctic from Alaska to Canada to Siberia store twice as much carbon as currently resides in the atmosphere — hundreds of billions of tons — and most of it has been buried for centuries.
An international team, led by researchers at Stockholm University, found that from 2000 to 2020, carbon dioxide uptake by the land was largely offset by emissions from it. Overall, they concluded that the region has been a net contributor to global warming in recent decades in large part because of another greenhouse gas, methane, that is shorter-lived but traps significantly more heat per molecule than carbon dioxide.
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Greenhouse gases shroud the globe in this animation showing data from 2021. Carbon dioxide is shown in orange; methane is shown in purple. Methane traps heat 28 times more effectively than carbon dioxide over a 100-year timescale. Wetlands are a significant source of such emissions.NASA’s Scientific Visualization Studio The findings reveal a landscape in flux, said Abhishek Chatterjee, a co-author and scientist at NASA’s Jet Propulsion Laboratory in Southern California. “We know that the permafrost region has captured and stored carbon for tens of thousands of years,” he said. “But what we are finding now is that climate-driven changes are tipping the balance toward permafrost being a net source of greenhouse gas emissions.”
Carbon Stockpile
Permafrost is ground that has been permanently frozen for anywhere from two years to hundreds of thousands of years. A core of it reveals thick layers of icy soils enriched with dead plant and animal matter that can be dated using radiocarbon and other techniques. When permafrost thaws and decomposes, microbes feed on this organic carbon, releasing some of it as greenhouse gases.
Unlocking a fraction of the carbon stored in permafrost could further fuel climate change. Temperatures in the Arctic are already warming two to four times faster than the global average, and scientists are learning how thawing permafrost is shifting the region from being a net sink for greenhouse gases to becoming a net source of warming.
They’ve tracked emissions using ground-based instruments, aircraft, and satellites. One such campaign, NASA’s Arctic-Boreal Vulnerability Experiment (ABoVE), is focused on Alaska and western Canada. Yet locating and measuring emissions across the far northern fringes of Earth remains challenging. One obstacle is the vast scale and diversity of the environment, composed of evergreen forests, sprawling tundra, and waterways.
This map, based on data provided by the National Snow and Ice Data Center, shows the extent of Arctic permafrost. The amount of permafrost underlying the surface ranges from continuous — in the coldest areas — to more isolated and sporadic patches.NASA Earth Observatory Cracks in the Sink
The new study was undertaken as part of the Global Carbon Project’s RECCAP-2 effort, which brings together different science teams, tools, and datasets to assess regional carbon balances every few years. The authors followed the trail of three greenhouse gases — carbon dioxide, methane, and nitrous oxide — across 7 million square miles (18 million square kilometers) of permafrost terrain from 2000 to 2020.
Researchers found the region, especially the forests, took up a fraction more carbon dioxide than it released. This uptake was largely offset by carbon dioxide emitted from lakes and rivers, as well as from fires that burned both forest and tundra.
They also found that the region’s lakes and wetlands were strong sources of methane during those two decades. Their waterlogged soils are low in oxygen while containing large volumes of dead vegetation and animal matter — ripe conditions for hungry microbes. Compared to carbon dioxide, methane can drive significant climate warming in short timescales before breaking down relatively quickly. Methane’s lifespan in the atmosphere is about 10 years, whereas carbon dioxide can last hundreds of years.
The findings suggest the net change in greenhouse gases helped warm the planet over the 20-year period. But over a 100-year period, emissions and absorptions would mostly cancel each other out. In other words, the region teeters from carbon source to weak sink. The authors noted that events such as extreme wildfires and heat waves are major sources of uncertainty when projecting into the future.
Bottom Up, Top Down
The scientists used two main strategies to tally greenhouse gas emissions from the region. “Bottom-up” methods estimate emissions from ground- and air-based measurements and ecosystem models. Top-down methods use atmospheric measurements taken directly from satellite sensors, including those on NASA’s Orbiting Carbon Observatory-2 (OCO-2) and JAXA’s (Japan Aerospace Exploration Agency)Greenhouse Gases Observing Satellite.
Regarding near-term, 20-year, global warming potential, both scientific approaches aligned on the big picture but differed in magnitude: The bottom-up calculations indicated significantly more warming.
“This study is one of the first where we are able to integrate different methods and datasets to put together this very comprehensive greenhouse gas budget into one report,” Chatterjee said. “It reveals a very complex picture.”
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Jane J. Lee / Andrew Wang
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0307 / 626-379-6874
jane.j.lee@jpl.nasa.gov / andrew.wang@jpl.nasa.gov
Written by Sally Younger
2024-147
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Last Updated Oct 29, 2024 Related Terms
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By USH
Miners of the Elga coal deposit (Yakut) in Siberia dug up a strange statue in the form of a woman with a sword and shield, and behind it there seem to be wings, like a fallen angel. The statue was unearthed by an excavator.
Miners show their emotions and enthusiasm when they are standing next to the statue. If the translation is right, they say that they cannot describe or tell what it is and that right now the special services will arrive by helicopter to pick up the statue to an unknown location.
Further study and examination by experts may be required to determine the significance of this potentially valuable ancient artifact, but since the special services are involved, it remains to be seen whether we will hear anything about it in the future.
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By USH
48,500 years old Zombie Virus Resurrected In French Lab..As the world warms up, vast tranches of permafrost are melting, releasing material that's been trapped in its icy grip for years. This includes a slew of microbes that have lain dormant for hundreds of millennia in some cases.
To study the emerging microbes, scientists have now revived a number of these "zombie viruses" from Siberian permafrost, including one thought to be nearly 50,000 years old – a record age for a frozen virus returning to a state capable of infecting other organisms.
The team behind the work, led by microbiologist Jean-Marie Alempic from the French National Centre for Scientific Research, says these reanimating viruses are potentially a significant threat to public health, and further study needs to be done to assess the danger that these infectious agents could pose as they awake from their icy slumber.
"One quarter of the Northern Hemisphere is underlain by permanently frozen ground, referred to as permafrost," write the researchers in their paper.
"Due to climate warming, irreversibly thawing permafrost is releasing organic matter frozen for up to a million years, most of which decompose into carbon dioxide and methane, further enhancing the greenhouse effect."
The 48,500-year-old amoeba virus is actually one of 13 outlined in a new study currently in preprint, with nine of them thought to be tens of thousands of years old. The researchers established that each one was distinct from all other known viruses in terms of their genome.
While the record-breaking virus was found beneath a lake, other extraction locations included mammoth wool and the intestines of a Siberian wolf – all buried beneath permafrost. Using live single-cell amoeba cultures, the team proved that the viruses still had the potential to be infectious pathogens.
We're also seeing huge numbers of bacteria released into the environment as the world warms up, but given the antibiotics at our disposal it might be argued they would prove less threatening. A novel virus – as with SARS-CoV-2 – could be much more problematic for public health, especially as the Arctic becomes more populated.
"The situation would be much more disastrous in the case of plant, animal, or human diseases caused by the revival of an ancient unknown virus," write the researchers.
"It is therefore legitimate to ponder the risk of ancient viral particles remaining infectious and getting back into circulation by the thawing of ancient permafrost layers."
This team has form for diligently digging up viruses in Siberia, with a previous study detailing the discovery of a 30,000-year-old virus. Like the new record holder, that was also a pandoravirus, a giant big enough to be visible using light microscopy.
The revived virus has been given the name Pandoravirus yedoma, which acknowledges its size and the type of permafrost soil that it was found in. The researchers think there are many more viruses to find too, beyond those that only target amoebas.
Many of the viruses that will be released as the ice thaws will be completely unknown to us – although it remains to be seen how infectious these viruses will be once they're exposed to the light, heat and oxygen of the outdoor environment. These are all areas that could be investigated in future studies.
Virologist Eric Delwart from the University of California, San Francisco, agrees that these giant viruses are just the start when it comes to exploring what lies hidden beneath the permafrost. Though Delwart wasn't involved in the current study, he has plenty of experience resuscitating ancient plant viruses.
"If the authors are indeed isolating live viruses from ancient permafrost, it is likely that the even smaller, simpler mammalian viruses would also survive frozen for eons."
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By European Space Agency
One of the many serious consequences of the climate crisis is that precious permafrost is thawing, and this is unleashing even more carbon to the atmosphere and further exacerbating climate change. However, it’s complicated. For example, sometimes permafrost can thaw rapidly and scientists are unsure why and what these abrupt thaws mean in terms of feedback loops. This makes it difficult to predict the future impact on the climate. Thanks to an ESA–NASA initiative, new research digs deep into understanding the complexities of permafrost thaw and how carbon is released over time.
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