Virginia Tech researchers point out that estimates of the carbon cycle – crucial for predicting climate change – are inaccurate.
[obligatory disclaimers sprinkled throughout ha~cr]
The findings do not refute the established science of climate change, but do indicate that the calculation of carbon removed by plants and returned by the soil is inaccurate.
VIRGINIA TECH
Virginia Tech researchers, in collaboration with the Pacific Northwest National Laboratory, have discovered that important parts of the global carbon cycle are used to track the movement of carbon dioxide in the environment. field is imprecise, which can dramatically alter conventional carbon cycle models.
Estimating the amount of carbon dioxide that plants take up from the atmosphere is important for accurately tracking and predicting the amount of climate-changing gases in the atmosphere. This finding has the potential to change predictions of climate change, although it is unclear at this time if the mismatch will result in more or less carbon dioxide being produced in the environment.
Meredith Steele, an assistant professor in the field School of Plant and Environmental Sciences inside College of Agriculture and Life Sciences, who had a PhD student at the time, Jinshi Jian, led the research team. The findings will be published on Friday at Nature Communications.
“We’re not challenging well-established climate change science, but we can account for all the carbon in the ecosystem and it’s not possible right now,” she said. “What we’ve found is that ecosystem models of climate change response need to be updated.”
Jian and Steele’s work focuses on the carbon cycle and how plants and soil remove and return carbon dioxide in the atmosphere.
To understand how carbon affects ecosystems on Earth, it’s important to know exactly where all the carbon is going. This process, known as carbon accounting, shows where and how much carbon is going to each of Earth’s carbon sinks such as oceans, atmosphere, land and living things.
For decades, researchers have been trying to figure out exactly where our carbon is and where it’s going. Virginia Tech and Pacific Northwest National Laboratory researchers focused on carbon dioxide that is sucked out of the atmosphere by plants through photosynthesis.
When animals eat plants, carbon moves into terrestrial ecosystems. Then it moves into the soil or to animals. And large amounts of carbon are also exhaled – or respired – back into the atmosphere.
This incoming and outgoing carbon dioxide is needed to balance the amount of carbon in the atmosphere, contributing to climate change and long-term carbon storage.
However, Virginia Tech researchers found that when using accepted numbers for soil respiration, that number in the carbon cycle models no longer balances out.
“Photosynthesis and respiration are the drivers of the carbon cycle, yet the annual totals of each of these elements at scale,” said Lisa Welp, associate professor of earth, atmospheric and planetary sciences at Purdue. global is difficult to measure. University, who are familiar with the work but not part of the study. “The authors’ efforts to reconcile these global estimates from different communities show us that they are not entirely self-consistent, and that much remains to be learned about these underlying processes across the globe. planet”.
What Jian and Steele, along with the rest of the team, discovered was that by using the total primary yield of accepted quantities of carbon dioxide of 120 petagrams – one petagram is one billion tons – the amount of carbon released out through soil respiration would be in the vicinity of 65 petagrams.
By analyzing multiple streams, the amount of carbon exchanged between Earth’s carbon sinks in the oceans, atmosphere, soil, and organisms, researchers have discovered that the amount of soil carbon that respiration takes Absorption out of the soil is about 95 petagrams. Total primary productivity should be around 147. For scale, the difference between the currently accepted amount is 120 petagrams and this estimate is about three times global fossil fuel emissions per year.
According to the researchers, there are two possibilities. The first is that remote sensing methods may be underestimating total primary production. The other approach is to upgrade soil respiration measurements, which may overestimate the amount of carbon returned to the atmosphere. Whether this fallacy is a positive or negative for the scientifically proven challenge of climate change is something to be considered, Steele said.
The next step of the study is to determine which parts of the global carbon cycle model are under or overestimated.
Jian, who started this research as a PhD, said that by accurately calculating carbon and its place in the ecosystem, better predictions and models will be able to accurately assess responses of these ecosystems to climate change. student at Virginia Tech and currently studying at Northwest A&F University in China.
“If we think back to the world when we were young, the climate has changed,” says Jian. “We have more extreme weather events. This study will improve the models we’ve used for carbon cycling and make better predictions about what the climate will look like in the future. ”
As Steele’s first PhD student at Virginia Tech, a portion of Steele’s start-up fund was used to support Jian’s graduate research. Jian, enamored with data science, databases, and soil respiration, was working on another part of his thesis when he came across something that didn’t quite fit.
Jian is working on how to make small, local carbon measurements from around the world. While researching this, Jian discovered that the best estimates do not match if all the global carbon computational flows are aggregated.
The research was funded by Steele’s start-up fund from the College of Agriculture and Life Sciences at Virginia Tech and further supported by the Pacific Northwest National Laboratory.
JOURNEYS
Nature Communications
DOI
RESEARCH SUBJECTS
Do not apply
ARTICLE TITLE
Historically inconsistent respiratory flow and productivity in the global terrestrial carbon cycle
ARTICLE PUBLICATION DATE
April 1, 2022
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