geoengineering explained: the benefits and challenges of biochar

Biochar, a form of carbon dioxide sequestration (SDR), is a solid material obtained from the carbonization of biomass. This produces a highly porous charcoal. The biomass is then buried in order to lock the carbon into the soil which can improve soil functions and the CO2 typically produced by the natural degradation of biomass is reduced. This practice is over 2,000 years old and biochar can be found throughout the world as a result of forest fires and historic soil management practices.

BENEFITS

CHALLENGES

  • Slows actual climate change, rather than actively changing the climate itself
  • Slows the rate of ocean acidification
  • Enhances the soil and can be made from waste products, such as chicken manure
  • Sustainable biochar practices can produce oil and gas byproducts that can be used as fuel, providing clean, renewable energy
  • Measurable and verifiable carbon sequestration value
  • Competes with global fuel and food production
  • Will not prevent sea-level rises
  • Has questionable efficacy and is predicted to only have the ability to offset 10 percent of the warming caused by increases in CO2

see also:

Question: What is geoengineering?

Albedo Enhancement

Space Reflectors
Stratospheric Aerosols

Afforestation
Ambient Air Capture
Biochar
Bioenergy Capture and Sequestration
Ocean Fertilization
Enhanced Weathering
Ocean Alkalinity Enhancement

sources:
Initiative, I. B. (2014). What is Biochar? Retrieved from biochar-international.org: http://www.biochar-international.org/biochar
Ippolito, J. a. (2011, March 3-4). Biochar usage: pros and cons. Retrieved from http://eprints.nwisrl.ars.usda.gov/1522/
LePage, M. (2012, September 20). The pros and cons of geoengineering. 

geoengineering explained: the benefits and challenges of enhanced weathering

Enhanced weathering is the process of exposing large quantities of minerals that are reactive with carbon dioxide in the atmosphere and storing the resulting compound in the ocean or soil. It is considered a form of carbon dioxide removal or CDR.

BENEFITS

CHALLENGES

  • Has the potential to increase terrestrial and oceanic net productivity
  • Can be used to improve agricultural output
  • Dependent on fossil fuels for execution which may reduce overall efficacy
  • Insufficient data and inability to accurately predict how fluxes in nutrients will impact Earth’s various systems
  • Applications of rock powder to the land’s surface may increase overall dust
  • The mobilization of potentially toxic chemicals from silicate rocks may detrimentally affect the food chain

see also:

Question: What is geoengineering?

Albedo Enhancement

Space Reflectors
Stratospheric Aerosols

Afforestation
Ambient Air Capture
Biochar
Bioenergy Capture and Sequestration
Ocean Fertilization
Enhanced Weathering
Ocean Alkalinity Enhancement

source:
Jens Hartmann, A. J.-G. (2013, May 23). Enhanced chemical weathering as a geoengineering strategy to reduce atmospheric carbon dioxide, supply nutrients, and mitigate ocean acidification. Review of Geophysics, pp. 113-149. 

geoengineering explained: the benefits and challenges of ocean alkalinity enhancement

Ocean alkalinity enhancement is increasements in the ocean’s alkalinity via the exposure of large quantities of reactive minerals to carbon dioxide in the atmosphere. The resulting compounds are then stored in the ocean or soil. This form of geoengineering is known as carbon dioxide removal (CDR).

BENEFITS

CHALLENGES

  • Increased solubility of CO2 in ocean waters
  • Sequestered carbon becomes inorganic carbon that stays in the ocean permanently
  • Expensive [estimates at more than 1 trillion USD]
  • There is a lack of infrastructure needed to effectively facilitate the transformation from limestone to quicklime
  • Has the potential to release more CO2 into the atmosphere if proper storage and capture facilities are not established
  • Can be harmful to biotic aquatic systems
  • Alkalinity must be significantly increased to produce worthwhile results

see also:

Question: What is geoengineering?

Albedo Enhancement

Space Reflectors
Stratospheric Aerosols

Afforestation
Ambient Air Capture
Biochar
Bioenergy Capture and Sequestration
Ocean Fertilization
Enhanced Weathering
Ocean Alkalinity Enhancement

sources:

Ian S F Jones, C. H. (2003, May). Engineering Carbon Sequestration in the Ocean. Retrieved from http://www.netl.doe.gov/publications/proceedings/03/carbon-seq/PDFs/111.pdf
Francois S. Paquay, R. E. (2013, May 9). Assessing possible consequences of ocean liming on ocean pH, atmospheric CO2 concentration and associated costs. International Journal of Greenhouse Gas Control, pp. 183-188. Retrieved from http://www.soest.hawaii.edu/oceanography/faculty/zeebe_files/Publications/Paquay13.pdf

geoengineering explained: the benefits and challenges of bioenergy with carbon capture and sequestration

The production of bioenergy with carbon capture and sequestration is considered a form of carbon dioxide removal (CDR). The process begins by growing biomass, burning it to create energy and finally capturing and sequestering the carbon dioxide created in the process. Negative CO2 emissions are generated by combining bio-energy production [biomass fuel power stations, pulp mills and biofuel plants] with carbon capture and storage technology, allowing carbon dioxide to be captured from the atmosphere and remitted back underground. 

BENEFITS

CHALLENGES

  • Can be fueled by any non-fossilized material of biological origin
  • Encourages the use of renewable energy sources
  • Provides opportunities for intersectoral collaborations and partnership development
  • Dependent on the cost of carbon emissions and the prices must be high enough for the process to be economically viable
  • Unproven technology that is expensive to develop.
  • Can only be applied to biomass to yield “negative emission” energy
  • A large number of operations are necessary in order to achieve results

see also:

Question: What is geoengineering?

Albedo Enhancement

Space Reflectors
Stratospheric Aerosols

Afforestation
Ambient Air Capture
Biochar
Bioenergy Capture and Sequestration
Ocean Fertilization
Enhanced Weathering
Ocean Alkalinity Enhancement

sources:

BECCS – Bio-Energy with Carbon Capture and Storage. (2010). Retrieved from http://www.thenaturalstep.org
International Energy Agency. (2011). Combining Bioenergy with CSS. Retrieved from iea.org: http://www.iea.org/publications/freepublications/publication/bioenergy_ccs.pdf

geoengineering explained: the benefits and challenges of space reflectors

Space reflectors, a form of solar radiation management (SRM), are sun shields positioned in space in order to reduce the amount of solar energy reaching the earth. Options include placing mirrors around the earth, placing millions of reflectors between the earth and the sun where the gravitational attraction between the two bodies is equal, launching a “cloud” of trillions of refracting discs or launching a sunshade of mesh aluminum threads.

BENEFITS

CHALLENGES

  • The theorized sun protection would be enough to stop global warming
  • Expensive [estimated at several trillion dollars]
  • Experimental technology with unforeseen consequences
  • Will take 25 years or longer to complete
  • Effects would be uneven with the tropics cooling and the polar regions warming

see also:

Question: What is geoengineering?

Albedo Enhancement

Space Reflectors
Stratospheric Aerosols

Afforestation
Ambient Air Capture
Biochar
Bioenergy Capture and Sequestration
Ocean Fertilization
Enhanced Weathering
Ocean Alkalinity Enhancement

sources:
Physics, I. I., RSC, & Engineering, T. R. (2009, July 15). Geoengineering: challenges and global impacts. Retrieved from http://www.rsc.org

 

geoengineering explained: the benefits and challenges of ocean fertilization

Ocean fertilization is an untested carbon dioxide sequestration (CDR) technique that involves dissolving nitrates or iron into the water which will encourage an increase in carbon uptake by phytoplankton. After the plankton blooms, it dies and then sinks to the ocean floor where the carbon will be stored as sedimentary rock.

BENEFITS

CHALLENGES

  • Relatively safe
  • Will slow the rate of ocean acidification
  • Does not directly change the actively changing climate, rather it slows future climate change
  • Will alter marine systems creating new potential problems
  • Will cause and/or accelerate ocean eutrophication

 

see also:

Question: What is geoengineering?

Albedo Enhancement

Space Reflectors
Stratospheric Aerosols

Afforestation
Ambient Air Capture
Biochar
Bioenergy Capture and Sequestration
Ocean Fertilization
Enhanced Weathering
Ocean Alkalinity Enhancement

sources:
The Editors of Encyclopædia Britannica. (2014). Ocean Fertilization. Retrieved from Britannica.com: http://www.britannica.com/EBchecked/topic/1563580/ocean-fertilization
LePage, M. (2012, September 20). The pros and cons of geoengineering. Retrieved from www.newscientist.com

geoengineering explained: the advantages and disadvantages of ambient air capture

Ambient air capture, a form of carbon dioxide sequestration (CDR), involves building large machines that can remove carbon dioxide directly from the ambient air so that the captured CO2 can be stored elsewhere. The three steps of the air capture process are:

  1. Contacting the air
  2. Absorption or adsorption on a sorbent
  3. Recovery of the sorbent

 

aircap_simplewhatis
the process of ambient air capture, image credit: carbonengineering.com

 

BENEFITS

DISADVANTAGES

  • Manages emissions originating from any source
  • Full-scale operations are able to absorb significant amounts of carbon, e.g. emissions from 300,000 cars
  • Can remove far more CO2 per acre of land footprint than trees and plants
  • Enables the direct extraction of CO2 from the atmosphere
  • Requires an energy source
  • Large volumes of air must be processed in order to collect meaningful amounts of CO2
  • Expensive

 

image-20150803-6016-156ods
ambient air capture, image credit: centerforcarbonremoval.org

 

see also:

Question: What is geoengineering?

Albedo Enhancement

Space Reflectors
Stratospheric Aerosols

Afforestation
Ambient Air Capture
Biochar
Bioenergy Capture and Sequestration
Ocean Fertilization
Enhanced Weathering
Ocean Alkalinity Enhancement

sources:
Carbon Engineering Ltd. (n.d.). What is air capture? Retrieved from http://www.carbonengineering.com
Lackner, K. S., Brennan, S., Matter, J. M., Park, A.-H. A., Wright, A., & Zwaan, B. v. (2012, June 28). The urgency of the development of CO2 capture from ambient air. Retrieved from http://www.energy.columbia.edu