When the river runs high

river
River Kvirila at Sachkhere, Georgia. Credit: Wikipedia

A massive world-wide study of dry riverbeds has found they're contributing more carbon emissions than previously thought, and this could help scientists better understand how to fight climate change.

Dr. Nathan Waltham from the Tropical Water and Aquatic Eco-systems Research Centre (TropWATER) and James Cook University in Australia, joined scientists from 22 other countries who looked at 212 dry riverbeds on every continent on earth.

He said the contribution of intermittent rivers and to the process of carbon cycling—the process by which carbon is circulated around the ecosystem—is largely ignored.

"There is a substantial amount of plant litter that accumulates in dry riverbeds and when they flow again this material can breakdown rapidly. We've now estimated the potential short-term CO2 emissions during these rewetting events."

"We believe that a single pulse of CO2 upon litter rewetting contributes up to 10% of the daily CO2 emission compared to perennial rivers and streams, particularly in temperate climates. What this means is that the contributions of intermittent rivers and streams should be included in global carbon-cycling assessments," said Dr. Waltham.

The scientists found that aridity, surrounding vegetation, channel width and dry-phase duration explained most variability in the quantity and decomposability of .

He said that the new data shows the contribution of CO2 from intermittent rivers and streams is higher than previously thought.

"Taking rivers and streams that only flow at certain times into account would improve estimates of the consequences of global on carbon cycling—given that the extent of these rivers and streams will increase, and periods of drying will become more prolonged in many regions," said Dr. Waltham.

About the research

Intermittent rivers, as the name suggests, sometimes stop flowing and can dry completely. Although far less studied than permanent rivers, they could represent half of the world's river network and, in response to change and increasing water demands, may come to dominate the landscape in some regions.

The results of this global study have been published in Nature Geosciences.


Explore further

Streams may emit more carbon dioxide in a warmer climate

More information: T. Datry et al, A global analysis of terrestrial plant litter dynamics in non-perennial waterways, Nature Geoscience (2018). DOI: 10.1038/s41561-018-0134-4
Journal information: Nature Geoscience

Citation: When the river runs high (2018, June 15) retrieved 15 October 2019 from https://phys.org/news/2018-06-river-high.html
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Jun 16, 2018
if you are actually worried about climate change tell algore and company to stop flying chartered jets. Plant trees. Paint artificial sky facing surfaces white.


Jun 17, 2018
if you are actually worried about climate change tell algore and company to stop flying chartered jets. Plant trees. Paint artificial sky facing surfaces white.



Good comment and so true. I gave you a Five and some jerk gave you a One, the bitter clinger.
Another mostly untenable solution for the dry riverbed problem would be for algore and his CC cohorts to roll up some sleeves and clean out those dry riverbeds of old vegetation and throw the stuff into a giant compost pile. Mix it with well-rotted cattle manure, worms, egg shells, water, etc. and you have a good commercial fertiliser that gardeners would pay well for.
Algore would demand his cut of the action, of course.

Jun 17, 2018
Ban dry riverbeds! Concrete them over!!

Jun 17, 2018
Just a reminder that the estimates on human impact on climate forcing has huge error bars:

http://www.aph.go...ig-2.jpg

We're not at all sure what the human caused greehouse effect is. It's has been simply assumed that man is responsible for most of the excess GHG emissions, especially on CO2, but little streams like these that are found every year add up to fill that gap in knowledge.

While the difference probably does not end up tipping the scales all the other way, the consequences for climate change mitigation are important because it means we can't just de-industrialize and shut everything down and fix things that way - we need to take a more active role in actually implementing negative GHG schemes.

Jun 17, 2018
Ah, you deniers and your agitprop lies. Your all angry because your masters are not allowed to set rivers on fire, anymore!

Jun 17, 2018
We're not at all sure what the human caused greehouse effect is. It's has been simply assumed that man is responsible for most of the excess GHG emissions, especially on CO2, but little streams like these that are found every year add up to fill that gap in knowledge.

Do you have evidence that the number of dry rivers has increased over time?

Jun 17, 2018
This comment has been removed by a moderator.

Jun 18, 2018
GHG emissions from the decay of animals and vegetation have been ongoing since the advent of the first single-celled animals/bacteria/plant-life billions of years before the present. But even long before that the Earth itself was emitting GHGs through geological processes such as vulcanism; long before life was created in the waters of Earth. It is only in the past and current centuries that some have been able to measure the content of the atmosphere and waters, and declared them to be unfit for humans/animals/plants to live under.
Before current measuring by hockey stick models there was no such thing as a Climate scientist. But, suddenly there was a whole industry of well-funded people whose careers involved bringing to attention the processes that had been going on for BILLIONS OF YEARS on the Earth.
And NOW, it was MAN'S FAULT. Not the dinosaurs; not volcanic action; not the ordinary ebb and flow of natural global processes. "Get rid of humans" is the possible answer.

Jun 18, 2018
I'll take Eikka's lack of a reply as acknowledgement that the number of dry rivers hasn't dramatically increased over time and therefore aren't a likely source of the observed 60% increase in CO2 levels since the Industrial Revolution.

Jun 20, 2018
S_E_G, my offer still stands for any of you denier shills. You stand under a (natural) rain. I then turn a firehose of sewage (manmade) on you.

What you bumble boys are too chickenshit to admit is that piling additional problems onto what is all ready serious trouble? Fails to improve the situation.

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