A new study has revealed for the first time that the old carbon, stored in landscapes for thousands of years or more, can find its way back to the atmosphere as the CO2 released from the surfaces of the rivers.
The findings, led by scientists from the University of Bristol and the cover history of the magazine Nature, It is likely that the average plants and shallow layers eliminate around a gigatonne plus CO2 each year of the atmosphere to counteract this, emphasizing its fundamental and greater part in the combination of climate change.
The main author, Dr. Josh Dean, associate professor of biogeochemistry and future leaders of Ucri Future, at the University of Bristol, said: “The results surprised us because it turns out that old carbon stores are dripping much more in the atmosphere and then suggested suggested previous estimates.
“The implications are potentially huge for our understanding of global carbon emissions. Plants and trees take co2 From the atmosphere and then you can lock this carbon on the soils for thousands of years.
“Our findings show part of this old carbon, as well as the old rock coal, is filtering the rivers sideways and returning to the atmosphere. We still do not know how humans are affecting this old carbon flow, but we know that plants and trees must be more carbon of the atmosphere today to take into account this unrecognized liberation of old carbon.”
The rivers transport and release methane and carbon dioxide as part of the global carbon cycle. Until now, scientists believed that most of this was a rapid rotation derived from the recycling of the recent growth of plants: organic material broken down and taken to the river system in the last 70 years or so. This new study indicates otherwise, with more than half, around 60%, of the emissions attributed to long -term carbon stores accumulated for hundreds to thousands of years, or even more.
The International Research Team, led by scientists from the University of Bristol, the University of Oxford and the United Kingdom Ecology and Hydrology Center, studied more than 700 river reach from 26 different countries worldwide.
They took detailed measurements of carbon dioxide radiocarbon and river methane. Comparing carbon-14 samples levels in the river with a standard reference for the modern atmospheric co2The team was able to date the river carbon.
The Co -author Professor Bob Hilton, a professor of sedimentary geography at the University of Oxford, explained: “We discovered that about half of the emissions are young, while the other half is much older, released from the deep layers of the soil and the weathering of rocks that formed thousands and even millions of years ago.”
The investigation was supported by the financing of the Natural Environment Research Council for Research and Innovation of the United Kingdom (UCRI) (NERC).
Co-author Dr. Gemma Coxon, associate professor of Hydrology and future leaders of UCRI at the University of Bristol, said: “Rivers release worldwide on two carbon gigatons every year, compared to human activity that the results between 10-15 gigatons of carbon emissions. This is significant. To reevaluate these crucial parts of the global cycle of carbon.”
With a greater construction on these findings, researchers plan to explore how the age of the river carbon emissions varies between the rivers that the study could not capture, as well as investigate how the age of these emissions may have changed over time.
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