Volcanic ash could help reduce CO2 associated with climate change

Date:
September 29, 2020
Source:
University of Southampton
Summary:
Scientists investigating ways of removing carbon dioxide (CO2)
and other greenhouse gases from our atmosphere believe volcanic
ash could play an important role.



FULL STORY ========================================================================== University of Southampton scientists investigating ways of removing
carbon dioxide (CO2) and other greenhouse gases from our atmosphere
believe volcanic ash could play an important role.


==========================================================================
A team from the University's School of Ocean and Earth Science has
modelled the impact of spreading volcanic ash from a ship to an area of
ocean floor to help amplify natural processes which lock away CO2 in
the seabed. They found the technique has the potential to be cheaper, technologically simpler and less invasive than other techniques to remove harmful gases.

The researchers' findings are published in the journal Anthropocene.

Human-caused climate change is one of the most pressing topics in
contemporary science and politics. The impact of hundreds of years
of greenhouse gas emissions are becoming clearer every year, with
environmental changes including heatwaves, droughts, wildfires, and
other extreme weather events.

"As a result of overwhelming evidence, politicians have begun to take
steps towards incorporating emissions reductions into policies, such as
in the 2015 Paris Agreement with its long-term goal of ensuring that
global average temperatures do not exceed 2DEGC above pre-industrial
levels. However, it is becoming clear that to avoid the worst impacts of climate change, active greenhouse gas removal (GGR) will be required,"
explains study co-author and University of Southampton Professor of Geochemistry, Martin Palmer.

GGR techniques remove carbon dioxide and other gases from the atmosphere, thereby reducing the greenhouse effect, and in the longer term, slowing
climate change. There are numerous potential approaches to GGR, from the simple, such as reforestation, to the complex, such as actively removing
CO2 from the atmosphere.

Most volcanoes lie close to the oceans, and every year millions of tonnes
of volcanic ash falls into them and settles to the seafloor. Once there,
it increases carbon storage in marine sediments and reduces atmospheric
CO2 levels. This is important because the oceans are the greatest sink
of humanmade CO2 on Earth.

"One of the ways oceans lock away CO2 is by storing it in sediments on the seafloor as calcium carbonate and organic carbon. In our work, we discuss
how this natural process may be augmented by artificially adding ash to oceans," says Jack Longman, lead-author and former Post-Doctoral Research Assistant at the University of Southampton, who now holds a position
at the Institute for Chemistry and Biology of the Marine Environment
(ICBM), University of Oldenburg.

The scientists modelled the effect of distributing volcanic ash from
a ship to an area of ocean. The results suggest that this method could sequester as much as 2300 tonnes of CO2 per 50,000 tonnes of ash delivered
for a cost of $50 per tonne of CO2 sequestered -- much cheaper than most
other GGR methods. In addition, the approach is simply an augmentation of
a naturally occurring process, it does not involve expensive technology
and it does not require repurposing valuable agricultural land.

The scientists say further research is needed though to test the
efficiency of enhanced ash deposition in the oceans and to make sure
there are no unforeseen side effects, but initial indications suggest
that it could be applied easily and cheaply in many areas of the world.


========================================================================== Story Source: Materials provided by University_of_Southampton. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Jack Longman, Martin R. Palmer, Thomas M. Gernon. Viability of
greenhouse
gas removal via the artificial addition of volcanic ash to the
ocean.

Anthropocene, 2020; 100264 DOI: 10.1016/j.ancene.2020.100264 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/09/200929123717.htm

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