• Estimates of the carbon cycle - vital to

    From ScienceDaily@1:317/3 to All on Fri Apr 1 22:30:36 2022
    Estimates of the carbon cycle - vital to predicting climate change - are incorrect, new researchers show

    Date:
    April 1, 2022
    Source:
    Virginia Tech
    Summary:
    Researchers have discovered that key parts of the global carbon
    cycle used to track movement of carbon dioxide in the environment
    are not correct, which could significantly alter conventional carbon
    cycle models. This finding has the potential to change predictions
    for climate change, though it is unclear at this juncture if the
    mismatch will result in more or less carbon dioxide being accounted
    for in the environment.



    FULL STORY ========================================================================== Virginia Tech researchers, in collaboration with Pacific Northwest
    National Laboratory, have discovered that key parts of the global carbon
    cycle used to track movement of carbon dioxide in the environment are not correct, which could significantly alter conventional carbon cycle models.


    ==========================================================================
    The estimate of how much carbon dioxide plants pull from the atmosphere is critical to accurately monitor and predict the amount of climate-changing gasses in the atmosphere. This finding has the potential to change
    predictions for climate change, though it is unclear at this juncture if
    the mismatch will result in more or less carbon dioxide being accounted
    for in the environment.

    "Either the amount of carbon coming out of the atmosphere from the
    plants is wrong or the amount coming out of the soil is wrong," said
    Meredith Steele, an assistant professor in the School of Plant and Environmental Sciences in the College of Agriculture and Life Sciences,
    whose Ph.D. student at the time, Jinshi Jian, led the research team. The findings are to be published Friday in Nature Communications.

    "We are not challenging the well-established climate change science,
    but we should be able to account for all carbon in the ecosystem and
    currently cannot," she said. "What we found is that the models of the ecosystem's response to climate change need updating." Jian and Steele's
    work focuses on carbon cycling and how plants and soil remove and return
    carbon dioxide in the atmosphere.

    To understand how carbon affects the ecosystems on Earth, it's important
    to know exactly where all the carbon is going. This process, called carbon accounting, says how much carbon is going where, how much is in each of
    Earth's carbon pools of the oceans, atmosphere, land, and living things.



    ==========================================================================
    For decades, researchers have been trying to get an accurate accounting
    of where our carbon is and where it is going. Virginia Tech and Pacific Northwest National Laboratory researchers focused on the carbon dioxide
    that gets drawn out of the atmosphere by plants through photosynthesis.

    When animals eat plants, the carbon moves into the terrestrial
    ecosystem. It then moves into the soil or to animals. And a large amount
    of carbon is also exhaled -- or respirated -- back into the atmosphere.

    This carbon dioxide that's coming in and going out is essential for
    balancing the amount of carbon in the atmosphere, which contributes to
    climate change and storing carbon long-term.

    However, Virginia Tech researchers discovered that when using the accepted numbers for soil respiration, that number in the carbon cycling models
    is no longer balanced.

    "Photosynthesis and respiration are the driving forces of the carbon
    cycle, however the total annual sum of each of these at the global scale
    has been elusive to measure," said Lisa Welp, an associate professor of
    earth, atmospheric, and planetary sciences at Purdue University, who is familiar with the work but was not part of the research. "The authors'
    attempts to reconcile these global estimates from different communities
    show us that they are not entirely self-consistent and there is more
    to learn about these fundamental processes on the planet." What Jian
    and Steele, along with the rest of the team, found is that by using the
    gross primary productivity of carbon dioxide's accepted number of 120
    petagrams -- each petagram is a billion metric tons -- the amount of
    carbon coming out through soil respiration should be in the neighborhood
    of 65 petagrams.



    ==========================================================================
    By analyzing multiple fluxes, the amount of carbon exchanged between
    Earth's carbon pools of the oceans, atmosphere, land, and living things,
    the researchers discovered that the amount of carbon soil respiration
    coming out of the soil is about 95 petagrams. The gross primary
    productivity should be around 147. For scale, the difference between
    the currently accepted amount of 120 petagrams and this is estimate is
    about three times the global fossil fuel emissions each year.

    According to the researchers, there are two possibilities for this. The
    first is that the remote sensing approach may be underestimating gross
    primary production. The other is the upscaling of soil respiration measurements, which could be overestimating the amount of carbon returned
    to the atmosphere.

    Whether this misestimate is a positive or negative thing for the
    scientifically proven challenge of climate change is what needs to be
    examined next, Steele said.

    The next step for the research is to determine which part of the global
    carbon cycling model is being under or overestimated.

    By having accurate accounting of the carbon and where it is in the
    ecosystem, better predictions and models will be possible to accurately
    judge these ecosystems' response to climate change, said Jian, who began
    this research as a Ph.D. student at Virginia Tech and is now at Northwest
    A&F University in China.

    "If we think back to how the world was when we were young, the climate
    has changed," Jian said. "We have more extreme weather events. This
    study should improve the models we used for carbon cycling and provide
    better predictions of what the climate will look like in the future."
    As Steele's first Ph.D. student at Virginia Tech, a portion of Steele's
    startup fund went to support Jian's graduate research. Jian, fascinated
    with data science, databases, and soil respiration, was working on another
    part of his dissertation when he stumbled across something that didn't
    quite add up.

    Jian was researching how to take small, localized carbon measurements
    from across the globe. While researching this, Jian discovered that
    the best estimates didn't match up if all the fluxes of global carbon accounting were put together.

    The research was funded by Steele's startup fund from the College of Agriculture and Life Sciences at Virginia Tech and further supported by
    Pacific Northwest National Laboratory.


    ========================================================================== Story Source: Materials provided by Virginia_Tech. Original written by
    Max Esterhuizen. Note: Content may be edited for style and length.


    ========================================================================== Journal Reference:
    1. Jinshi Jian, Vanessa Bailey, Kalyn Dorheim, Alexandra G. Konings,
    Dalei
    Hao, Alexey N. Shiklomanov, Abigail Snyder, Meredith Steele,
    Munemasa Teramoto, Rodrigo Vargas, Ben Bond-Lamberty. Historically
    inconsistent productivity and respiration fluxes in the global
    terrestrial carbon cycle. Nature Communications, 2022; 13 (1) DOI:
    10.1038/s41467-022-29391- 5 ==========================================================================

    Link to news story: https://www.sciencedaily.com/releases/2022/04/220401094830.htm

    --- up 4 weeks, 4 days, 10 hours, 50 minutes
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)