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Out of all the possible alternatives for the solution to global warming, geoengineering is the most innovative and technologically aggressive of them. Geoengineering does not refer to a single technology but to all proposals that alter the environment of our planet. These proposals are intended to lessen the amount of carbon dioxide and solar rays hitting the earth. As the technology of the world grows more sophisticated, so do the possibilities for geoengineering expansion. Geoengineering may not be the final solution to solving global warming, but its applications can be used to dramatically lessen its effects.

Geoengineering is not focused on one single technology, but on large-scale alteration of the earth’s oceans, terrain, and atmosphere in order to slow down the global warming process. Geoengineering is an adaptation method, because it is only a short-term solution to a long term problem. It offers large scale solutions that could prevent a bad situation from getting worse and make a gradual implementation of mitigation methods possible. At the current pace of climate change, geoengineering may be a solution of final resort.

Solar Shields

The implementation of solar reflectors into outer space is one of the most prominent of geoengineering schemes. One proposal involves putting 16 trillion refracting discs into space in order to reflect 2% of the suns rays.[1] This would reduce the burden of the sun on the climate and offset the increased amount of carbon dioxide. Despite the promising technology, it requires vast amounts of resources which could only be attained through international cooperation.[2] This method would also reduce annual rainfall by 2%, increasing the likelihood of droughts in an increasing populated world. In addition, solar shields have the potential to be used as weapons.

Stratospheric Aerosols

The explosion of Mount Pinatubo in 1991 presented hope for input of sulfur into the atmosphere. The global ban on aerosols provided a precursor for effective global initiative to stop a potentially catastrophic event in the depletion of the ozone layer. Ironically, aerosols are now considered as part of the solution to slow down the global warming process.[3]An immense volcanic eruption such as Mount Pinatubo correlates with global decrease in temperatures. The large amounts of ash serve as a blanket that blocks solar rays. The explosion of Mount Pinatubo in 1991 caused a dip in global temperatures, and presented an anomaly in the constantly increasing temperatures occurring each year. The input of half the amount of sulfur from Pinatubo into the atmosphere every year would counterbalance the effect of greenhouse gases. The risk is that all the sulfur can damage the stratospheric ozone layer.[4]

Ocean Sequestration and Fertilization

The vast surface area of the ocean also presents an opportunity to use technology in order to dump large amounts of carbon dioxide into the ocean. The ocean currently absorbs 80% of the carbon dioxide that is put into the atmosphere. One proposal for ocean sequestration involves tubes being placed underwater and phytoplankton bloom growth stimulated with iron in order to absorb the carbon dioxide.[5] This second phase is known as ocean fertilization and is designed to increase the amount of carbon dioxide the ocean can absorb. However, opposition on the issue is based on the uncertainties of the water’s chemistry. The massive amounts of carbon dioxide could change the ocean’s chemistry and further exacerbate the problem. It could present considerable damage to the organisms that exist in the oceans.

Economics and Cost-Benefit Analysis

Geoengineering is an expensive, large scale enterprise. Many of these technologies need further research and have not been implemented yet. Taking into account the cost-benefit analysis, geoengineering becomes more lucrative when the effects of climate change become too demanding on the global population. In comparison to mitigation, geoengineering presents fixed costs for proposals. Mitigation, on the other hand, depends on the amount being decreased in emissions.


  1. Sands, Derek. "Space mirrors to combat global warming? Scientists mull 'geoengineering' schemes." Inside Energy 09 06 2008 13. 29 Oct 2008 <>.
  2. Song, Vivian. "Reflecting on the weather; Geoengineering explores futuristic solutions to our climate change problems." The Toronto Son 20 January, 2008 24. 29 Oct 2008 <>.
  3. Wigley, T.M.L.. "A Combined Mitigation/Geoengineering Approach to Climate Stabilization ." Science Vol. 31420 October 2006 452-454. 21 Oct 2008 <>
  4. Wigley, T.M.L.. "A Combined Mitigation/Geoengineering Approach to Climate Stabilization ." Science Vol. 31420 October 2006 452-454. 21 Oct 2008 <>
  5. Zhou, S. and Flynn, P.C.. "GEOENGINEERING DOWNWELLING OCEAN CURRENTS: A COST ASSESSMENT." 29 April 2004 29 Oct 2008 <>.


Wigley, T.M.L.. "A Combined Mitigation/Geoengineering Approach to Climate Stabilization ." Science Vol. 31420 October 2006 452-454. 21 Oct 2008 <>.