Featured Research

from universities, journals, and other organizations

Scrubbing CO2 from atmosphere could be a long-term commitment

Date:
July 2, 2010
Source:
Carnegie Institution
Summary:
With carbon dioxide in the atmosphere approaching alarming levels, even halting emissions altogether may not be enough to avert catastrophic climate change. Could scrubbing carbon dioxide from the air be a viable solution? A new study suggests that while removing excess carbon dioxide would cool the planet, keeping carbon dioxide at low levels would require a long-term commitment spanning decades or even centuries.

With carbon dioxide in the atmosphere approaching alarming levels, even halting emissions altogether may not be enough to avert catastrophic climate change. Could scrubbing carbon dioxide from the air be a viable solution?

A new study by scientists at the Carnegie Institution suggests that while removing excess carbon dioxide would cool the planet, complexities of the carbon cycle would limit the effectiveness of a one-time effort. To keep carbon dioxide at low levels would require a long-term commitment spanning decades or even centuries.

Previous studies have shown that reducing carbon dioxide emissions to zero would not lead to appreciable cooling, because carbon dioxide already within the atmosphere would continue to trap heat. For cooling to occur, greenhouse gas concentrations would need to be reduced. "We wanted to see what the response would be if carbon dioxide were actively removed from the atmosphere," says study coauthor Ken Caldeira of Carnegie's Department of Global Ecology. "Our study is the first to look at how much carbon dioxide you would need to remove and for how long to keep atmospheric carbon dioxide concentrations low. This has obvious implications for the public and for policy makers as we weigh the costs and benefits of different ways of mitigating climate change."

For the study, Caldeira and lead author Long Cao, also at Carnegie, did not focus on any specific method of capturing and storing carbon dioxide from the ambient air. The possibilities include approaches as diverse as industrial-scale chemical technologies and changing land use so more carbon dioxide is naturally absorbed by vegetation. For the study, the researchers used an Earth system model under projected conditions at the middle of this century when global surface temperatures have been raised 2 C (3.6 F). They then simulated the effects of an idealized case in which carbon emissions were reduced to zero and carbon dioxide in the atmosphere was instantaneously restored to pre-industrial levels.

The researchers found that removing all human-emitted carbon dioxide from the atmosphere caused temperatures to drop, but it offset less than half of CO2-induced warming. Why would removing all the extra carbon dioxide have such a small effect? The researchers point to two primary reasons. First, slightly more than half of the carbon dioxide emitted by fossil-fuels over the past two centuries has been absorbed in the oceans, rather than staying in the atmosphere. When carbon dioxide is removed from the atmosphere, it is partially replaced by gas coming out of ocean water. Second, the rapid drop in atmospheric carbon dioxide and the change in surface temperature alters the balance of the land carbon cycle, causing the emission of carbon dioxide from the soil to exceed its uptake by plants. As a result, carbon dioxide is released back into the atmosphere.

According to the simulations, for every 100 billion tons of carbon removed from the atmosphere, average global temperatures would drop 0.16 C (0.28 F).

Further simulations showed that in order to keep carbon dioxide at low levels, the process of extracting carbon dioxide from the air would have to continue for many decades, and perhaps centuries, after emissions were halted.

"If we do someday decide that we need to remove carbon dioxide from the atmosphere to avoid a climate crisis, we might find ourselves committed to carbon dioxide removal for a long, long time. A more prudent plan might involve preventing carbon dioxide emissions now rather than trying to clean up the atmosphere later."


Story Source:

The above story is based on materials provided by Carnegie Institution. Note: Materials may be edited for content and length.


Cite This Page:

Carnegie Institution. "Scrubbing CO2 from atmosphere could be a long-term commitment." ScienceDaily. ScienceDaily, 2 July 2010. <www.sciencedaily.com/releases/2010/07/100701183601.htm>.
Carnegie Institution. (2010, July 2). Scrubbing CO2 from atmosphere could be a long-term commitment. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2010/07/100701183601.htm
Carnegie Institution. "Scrubbing CO2 from atmosphere could be a long-term commitment." ScienceDaily. www.sciencedaily.com/releases/2010/07/100701183601.htm (accessed July 28, 2014).

Share This




More Earth & Climate News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com
The Carbon Trap: US Exports Global Warming

The Carbon Trap: US Exports Global Warming

AP (July 28, 2014) AP Investigation: As the Obama administration weans the country off dirty fuels, energy companies are ramping-up overseas coal exports at a heavy price. (July 28) Video provided by AP
Powered by NewsLook.com
Raw: Sea Turtle Hatchlings Emerge from Nest

Raw: Sea Turtle Hatchlings Emerge from Nest

AP (July 27, 2014) A live-streaming webcam catches loggerhead sea turtle hatchlings emerging from a nest in the Florida Keys. (July 27) Video provided by AP
Powered by NewsLook.com
Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. Video provided by Newsy
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:
from the past week

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