Featured Research

from universities, journals, and other organizations

'Rock dissolving' method of geoengineering to mitigate climate change would not be easy

Date:
January 22, 2013
Source:
Institute of Physics (IOP)
Summary:
The benefits and side effects of dissolving particles in our ocean’s surfaces to increase the marine uptake of carbon dioxide, and therefore reduce the excess amount of it in the atmosphere, have been analyzed in a new study. Researchers calculate that if three gigatons of olivine were deposited into the oceans each year, it could compensate for only around nine per cent of present day anthropogenic CO2 emissions.

The benefits and side effects of dissolving particles in our ocean's surfaces to increase the marine uptake of carbon dioxide (CO2), and therefore reduce the excess amount of it in the atmosphere, have been analysed in a new study.
Credit: © honzakrej / Fotolia

The benefits and side effects of dissolving particles in our ocean's surfaces to increase the marine uptake of carbon dioxide (CO2), and therefore reduce the excess amount of it in the atmosphere, have been analysed in a new study.

Related Articles


The study, published Jan. 22 in IOP Publishing's journal Environmental Research Letters, assesses the impact of dissolving the naturally occurring mineral olivine and calculates how effective this approach would be in reducing atmospheric CO2.

The researchers, from the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany, calculate that if three gigatonnes of olivine were deposited into the oceans each year, it could compensate for only around nine per cent of present day anthropogenic CO2 emissions.

This long discussed 'quick fix' method of geoengineering is not without environmental drawbacks; the particles would have to be ground down to very small sizes (around one micrometre) in order to be effective. The grinding process would consume energy and therefore emit varying amounts of CO2, depending on the sort of power plants used to provide the energy.

Lead author of the study Peter Köhler said: "Our literature-based estimates on the energy costs of grinding olivine to such a small size suggest that with present day technology, around 30 per cent of the CO2 taken out of the atmosphere and absorbed by the oceans would be re-emitted by the grinding process."

The researchers used a computer model to assess the impact of six different olivine dissolution scenarios. Olivine is an abundant magnesium-silicate found beneath Earth's surface that weathers quickly when exposed to water and air -- in its natural environment it is dissolved by carbonic acid which is formed from CO2 out of the atmosphere and rain water.

If olivine is distributed onto the ocean's surface, it begins to dissolve and subsequently increases the alkalinity of the water. This raises the uptake capacity of the ocean for CO2, which is taken up via gas exchange from the atmosphere.

According to the study, 92 per cent of the CO2 taken up by the oceans would be caused by changes in the chemical make-up of the water, whilst the remaining uptake would be down to changes in marine life through a process known as ocean fertilisation.

Ocean fertilisation involves providing phytoplankton with essential nutrients to encourage its growth. The increased numbers of phytoplankton use CO2 to grow, and then when it dies it sinks to the ocean floor taking the CO2 with it.

"In our study we only examined the effects of silicate in olivine. Silicate is a limiting nutrient for diatoms -- a specific class of phytoplankton. We simulated with our model that the added input of silicate would shift the species composition within phytoplankton towards diatoms.

"It is likely that iron and other trace metals will also impact marine life if olivine is used on a large scale. Therefore, this approach can also be considered as an ocean fertilisation experiment and these impacts should be taken into consideration when assessing the pros and cons of olivine dissolution," continued Köhler.

The researchers also investigated whether the deposition of olivine could counteract the problem of ocean acidification, which continues to have a profound effect on marine life. They calculate that about 40 gigatonnes of olivine would need to be dissolved annually to fully counteract today's anthropogenic CO2 emissions.

"If this method of geoengineering was deployed, we would need an industry the size of the present day coal industry to obtain the necessary amounts of olivine. To distribute this, we estimate that 100 dedicated large ships with a commitment to distribute one gigatonne of olivine per year would be needed.

"Taking all our conclusions together -- mainly the energy costs of the processing line and the projected potential impact on marine biology -- we assess this approach as rather inefficient. It certainly is not a simple solution against the global warming problem." said Köhler.


Story Source:

The above story is based on materials provided by Institute of Physics (IOP). Note: Materials may be edited for content and length.


Journal Reference:

  1. Peter Köhler, Jesse F Abrams, Christoph Völker, Judith Hauck, Dieter A Wolf-Gladrow. Geoengineering impact of open ocean dissolution of olivine on atmospheric CO2, surface ocean pH and marine biology. Environmental Research Letters, 2013; 8 (1): 014009 DOI: 10.1088/1748-9326/8/1/014009

Cite This Page:

Institute of Physics (IOP). "'Rock dissolving' method of geoengineering to mitigate climate change would not be easy." ScienceDaily. ScienceDaily, 22 January 2013. <www.sciencedaily.com/releases/2013/01/130121192017.htm>.
Institute of Physics (IOP). (2013, January 22). 'Rock dissolving' method of geoengineering to mitigate climate change would not be easy. ScienceDaily. Retrieved March 26, 2015 from www.sciencedaily.com/releases/2013/01/130121192017.htm
Institute of Physics (IOP). "'Rock dissolving' method of geoengineering to mitigate climate change would not be easy." ScienceDaily. www.sciencedaily.com/releases/2013/01/130121192017.htm (accessed March 26, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Thursday, March 26, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Clean-Up Follows Deadly Weather in Okla.

Clean-Up Follows Deadly Weather in Okla.

AP (Mar. 26, 2015) — Gov. Mary Fallin has declared a state of emergency for 25 Oklahoma counties after powerful storms rumbled across the state causing one death, numerous injuries and widespread damage. (March 26) Video provided by AP
Powered by NewsLook.com
At Least Four Dead After Floods in Northern Chile

At Least Four Dead After Floods in Northern Chile

Reuters - News Video Online (Mar. 26, 2015) — At least four people have been killed by severe flooding in northern Chile after rains battered the Andes mountains and swept into communities below. Rob Muir reports. Video provided by Reuters
Powered by NewsLook.com
Oklahomans "devastated" By Tornado Damage

Oklahomans "devastated" By Tornado Damage

Reuters - US Online Video (Mar. 26, 2015) — Buildings and homes lay in ruins and a semi-truck gets flipped following a fierce tornado that left at least one person dead. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Tornado Tears Through Oklahoma Town

Tornado Tears Through Oklahoma Town

Reuters - US Online Video (Mar. 26, 2015) — Aerial video shows the moment a tornado ripped across the town of Moore, Oklahoma, sending sparks flying. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins