{"id":12405,"date":"2018-02-05t13:25:25","date_gmt":"2018-02-05t13:25:25","guid":{"rendered":"http:\/\/dpetrov.2create.studio\/planet\/wordpress\/can-soil-save-the-world\/"},"modified":"2023-03-07t19:39:39","modified_gmt":"2023-03-07t19:39:39","slug":"soil-can-save-the-world-how-microbes-are-already-mitigating-climate-change","status":"publish","type":"post","link":"\/\/www.getitdoneaz.com\/story\/soil-can-save-the-world-how-microbes-are-already-mitigating-climate-change\/","title":{"rendered":"can soil save the world?"},"content":{"rendered":"

the first kingdom to climb out of the primordial muck of earth\u2019s early ocean were fungi<\/a>.<\/p>\n

they pockmarked hard rock with acid while storing earth\u2019s carbon-dioxide-rich atmosphere into the ground.<\/p>\n

years later, plants and bacteria followed \u2014 establishing themselves in the porous beachheads the fungi carved-out.<\/p>\n

the three kingdoms became fast allies, and across a geological timescale of about 400 million years, have partnered in various ways to make earth the oxygen- and soil-rich world it is today.<\/p>\n

but human activity is throwing off the storied balance the kingdoms have built \u2014 most notably by emitting carbon dioxide that warms the planet. thankfully, earth\u2019s ecological system will step up to bat, and store or eat the problem greenhouse gases just as it always has. while the system can’t wholly make up for a human-induced imbalance of atmospheric carbon dioxide, scientists are finding ways for humans to resolve the crisis. the solutions, they say, are literally underneath our feet.<\/p>\n

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read more<\/h1>\n

learn more about how microbes can help us with sustainable technology<\/a>.<\/p>\n<\/div>\n

what about gas released from thawing ice?<\/h2>\n

methane, a greenhouse gas frozen by the megatons in earth\u2019s melting ice, holds the potential to dramatically turn up the thermostat for the planet. but new research shows that a bacterial hero from earth\u2019s soils and seas will keep the thawing gas at bay.<\/p>\n

methane-eating soil microbes will prevent large plumes of methane from reaching the atmosphere as frozen deposits of it begin to thaw due to climate change, according to a paper in nature<\/a> published by vasilii petrenko and jeffrey severinghaus of the scripps institution of oceanography at the university of california, san diego. while severinghaus doesn\u2019t study microbes directly, he\u2019s able to show their effect on past climates by going to antarctica and sampling ancient air.<\/p>\n

scientists previously thought thawing methane deposits may have caused an abrupt 50% rise in atmospheric methane concentration during a rapid warming period at the end of the younger dryas, a cold period that ended 11,600 years ago. the prospect raised alarms to a potentially devastating climate feedback from methane, which, molecule for molecule, traps at least 25 times more heat in the atmosphere than carbon dioxide.<\/p>\n

through 10 years of sampling ancient air, severinghaus, his graduate students and the rest of his team were able to show, however, that during the warming period, no detectable methane in the atmosphere came from thawed deposits.<\/p>\n

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\"ice
vasiliii petrenko works in the severinghaus lab, and went to antarctica to do ‘radiometric dating’ on ancient glacial ice. this chamber melts the ice so he can inspect the methane content, as the ice is representative of what was in the atmosphere 11,600 years ago during a rapid warming event. (photo courtesy jeffrey severinghaus)<\/figcaption><\/figure>\n<\/div>\n

they demonstrated this by looking at the radiocarbon content of 11,600-year-old antarctic ice, exhuming a ton for each measurement at a precise and narrow vein of ancient ice originally deposited by snowfall on younger dryas glaciers. they gathered a corresponding control of modern-day air, cleaned of carbon-14, for each measurement as well.<\/p>\n

carbon-14 is a naturally occurring radioactive carbon isotope. it builds up in the air and in all living organic things, as cosmic rays bombard atoms in the atmosphere, and is used in carbon dating. <\/p>\n

the carbon-14 distinction is important because methane released from thawed deposits has no carbon-14 \u2014 it\u2019s so old that the radiocarbon content decayed long ago. but methane released from natural sources such as wetlands is fresh, and does have detectable carbon-14. <\/p>\n

severinghaus said: \u201cif that 50% increase in methane concentration was actually caused by the tundra getting warm and burping out all of this methane, then the concentration of carbon-14 relative to the abundant carbon-12 should have gone down by 30%. we should really see a huge signal if this idea is correct \u2026 and we don\u2019t.\u201d<\/p>\n

he goes on to explain that methane-consuming soil microbes must have stopped most of the thawing methane from reaching the atmosphere \u2014 just as their oceanic cousins did when they ate 99.9% of the methane released during the deepwater horizon oil spill in 2010.<\/p>\n

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\"deepwater\"
deepwater horizon oil spill. (kris kr\u00fcg\/wikimedia<\/a>)<\/figcaption><\/figure>\n<\/div>\n

wetlands, which belch methane when it rains, and other natural sources were the main culprits for the rise in methane during the younger dryas warming period, severinghaus said.<\/p>\n

\u201cif it didn\u2019t happen back then, it won\u2019t happen now and it won\u2019t happen in the future,\u201d severinghaus said. \u201cwe can focus our attention back on carbon dioxide, which really is the problem, and not worry so much about methane. so check one thing off the list.\u201d<\/p>\n

but how do tiny soil microbes store carbon? <\/h2>\n

pockets of soil with low oxygen levels are the key to slowing dead-plant-eating and carbon-dioxide-emitting microbes.<\/p>\n

new research fleshes out the role these bb gun pellet-sized granules and clumps of dirt play in the global carbon cycle, concluding they help offset emissions from well-aerated soil. so-called \u201caerobic\u201d soil contributes a third of annual carbon dioxide emissions, and that may grow as low-oxygen, \u201canaerobic\u201d pockets get disturbed by warming and human activity, the authors report in their study published in nature<\/a>.<\/p>\n

study coauthor scott fendorf, professor of earth sciences at stanford, said, \u201cyour food might spoil faster at a higher temperature; that’s because the microbes are eating faster. so, in the soil, the same thing [happens], the microbes start decomposing the plant material more rapidly, and that means carbon dioxide is being made to a greater extent.”<\/p>\n

fendorf and his team were able to show how the current understanding of soil is flawed. climate models that deliver temperature projections often treat all upland soil \u2014 literally soil at a higher elevation \u2014 as aerated. the team found that pockets of asphyxiated soil can and have existed in such environments \u2014 thanks to periodic flooding or any number of oxygen-depriving natural occurrences. <\/p>\n

fendorf and his coauthors found spots where old, carbon-rich plant parts still existed. in a 100% aerobic environment they wouldn\u2019t be there, because energized-by-oxygen microbes would eat all the carbon and send it up to the atmosphere as a gas.<\/p>\n

the team learned that when microbes have to use a different gas for air, they work far less efficiently \u2014 emitting carbon dioxide at a tenth of the speed than well-aerated soil would.<\/p>\n

fendorf added that climate models are evolving to accurately portray the impact low-oxygen pockets have on the global carbon cycle.<\/p>\n

\u201cif the temperature and moisture content was all the same, then you could just calibrate models and you’d be fine,” fendorf said. “but when it starts shifting \u2014 if it gets warmer or it gets wetter or drier \u2014 then your model has to account for those changes” within both aerobic and anaerobic soils, allowing scientists to better track the resulting carbon dioxide levels.<\/p>\n

the authors say we can help retain the pockets where microbes are less efficient \u2014 and help reduce carbon emissions \u2014 by tilling soil less. the fewer passes a tiller makes, the fewer pockets spill their uneaten bits of carbon to hungry microbes. an increasing number of farmers already have reduced tilling<\/a> to help reduce their carbon footprints.<\/p>\n

but the authors also warn of an increase in the range of dry conditions caused by climate change. anaerobic pockets surrounded by compacted and moist dirt will bake and turn aerobic, and that will lead to more emissions, as long as it doesn\u2019t get too hot for the microbes to function efficiently.<\/p>\n

‘re-greening’ could cover 37% of co2 cuts needed by 2030<\/h2>\n

carbon capture and storage technologies are being deployed in a piecemeal way, ensuring a negligible impact on the atmosphere and its growing concentration of planet-warming carbon dioxide. photosynthesis however is alive and well, storing billions of tons of carbon each year.<\/p>\n