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

question: what is geoengineering?

Geoengineering is deliberate, large-scale intervention in Earth’s natural systems to counteract climate change. The two most common forms are:

SOLAR RADIATION MANAGEMENT (SRM)

SRM techniques aim to reflect a small proportion of the Sun’s energy back into space, counteracting the temperature rise caused by increased levels of greenhouse gases in the atmosphere which absorb energy and raise temperatures. Methods include: albedo enhancement, space reflectors and stratospheric aerosols.

CARBON DIOXIDE REMOVAL (CDR)

These techniques aim to remove carbon dioxide from the atmosphere, directly countering the increased greenhouse effect and ocean acidification. These techniques would have to be implemented on a global scale to have a significant impact on carbon(4). Methods include: afforestation, biochar, bioenergy capture and sequestration, ambient air capture, ocean fertilization, enhanced weathering and ocean alkalinity enhancement.

A description of the different forms can be found in the following posts:

SRM:

Albedo Enhancement

Space Reflectors
Stratospheric Aerosols

CDR:

Ambient Air Capture
Afforestation

Biochar
Bioenergy Capture and Sequestration
Ocean Fertilization
Enhanced Weathering
Ocean Alkalinity Enhancement

geoengineering explained: the benefits and challenges of stratospheric aerosols

Stratospheric aerosols are minute particles suspended in the atmosphere designed for solar radiation management (SRM). When these particles are sufficiently large, their presence becomes noticeable as they scatter and absorb sunlight, which can reduce visibility (haze) and redden sunrises and sunsets. Aerosols interact both directly and indirectly with the Earth’s radiation budget and climate. As a direct effect, the aerosols scatter sunlight directly back into space. As an indirect effect, aerosols in the lower atmosphere can modify the size of cloud particles, changing how the clouds reflect and absorb sunlight, thereby affecting the earth’s energy budget. Aerosols can also act as sites for chemical reactions to take place. Stratospheric aerosols introduce small, reflective particles into the upper atmosphere to reflect some sunlight before it reaches the surface of the Earth. This is accomplished by releasing sulfur dioxide into the stratosphere.

BENEFITS

CHALLENGES

  • Very potent method and could off-set all the warming from the doubling of CO2
  • Affordable and relatively easy
  • Proven effective by large, natural volcanic eruptions
  • As with all sunshade schemes, overall rainfall is reduced
  • Regional weather climates will be dramatically affected which may cause dangerous outcomes, such as famine
  • Doesn’t cool poles to pre-industrial temperatures, so polar ice sheets will continue to melt
  • Will not prevent ocean acidification
  • Sky will become whiter
  • Without efforts to reduce overall CO2 production, the planet would warm rapidly if we stopped injecting SO2 into the stratosphere

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:
LePage, M. (2012, September 20). The pros and cons of geoengineering. Retrieved from New Scientist: http://www.newscientist.com/gallery/geoengineering/

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