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Encyclopedia of Climate Change, Third Edition

Climate engineering

by Arpita Nandi

Category(s): Science and technology

Climate engineering is a species of geoengineering, an expansive field that ranges over a wide variety of subjects, combining the study of Earth’s atmosphere, lithosphere, and biospheres with practical engineering principles. The practice was suggested in the 1970’s by Cesare Marchetti as a means of mitigating the effect of burning fossil fuels by injecting carbon dioxide into the ocean depths.

Key Concepts

aerosols: microscopic particles of solid or liquid suspended in the atmosphere

biosphere: the realm of Earth’s living organisms

greenhouse gas: any atmospheric gas that can absorb infrared (heat) energy from Earth’s surface and then emit a significant portion of that energy back into the atmosphere rather than out into space

lithosphere: the rocky crust of the planet

DEFINITION

Climate engineering is a species of geoengineering, an expansive field that ranges over a wide variety of subjects, combining the study of Earth’s atmosphere, lithosphere, and biospheres with practical engineering principles. Also termed planetary engineering or macro engineering, the practice was suggested in the 1970’s by Cesare Marchetti, who envisioned mitigating climatic impacts from burning fossil fuels by injecting carbon dioxide (CO2) deep into the ocean. The term geoengineering then started to appear in publications by the National Academies of Science and entered the conventional climate change debate. Practitioners of geoengineering or climate engineering develop technologies for the large-scale, intentional manipulation of the global environment. The threat represented by the greenhouse effect has generated international concern among politicians, policy makers, scientists, and engineers, who are continuously trying to fight global climate change and control warming.

Climate engineering has gained a great deal of attention worldwide as a result of its potential to combat global warming. Goals of such engineering are to reduce the amount of solar radiation absorbed by Earth, control the atmospheric concentration of CO2, and manipulate the ocean-atmosphere system by redirecting heat.

METHODS OF CLIMATE ENGINEERING

Important climate engineering technologies and goals include use of atmospheric aerosols, CO2 sequestration, enhancing Arctic ice, use of ocean-cooling pipes, cloud seeding, genetically modified CO2-eating trees, space mirrors, and glacier blankets. Use of atmospheric aerosols and CO2 sequestration have gained the greatest reputation in the scientific community.

Aerosols are microscopic particles floating in the atmosphere. The chemical composition of aerosols can vary widely; however, the sulfate aerosols have aroused particular concern. There are two main types of atmospheric aerosols that influence Earth’s climate. Natural aerosols result from volcanoes, wildfires, desert dust, and terrestrial and marine biogenic activity. Anthropogenic aerosols include smoke particulates from burning fossil fuels and tropical forests, as well as by-products from industrial activity. Sulfate aerosols influence the global climate by scattering and absorbing solar radiation, increasing the albedo, and modifying the size and duration of clouds, which in turn produce a global cooling effect.

Proposed solar geoengineering using a tethered balloon to inject sulfate aerosols into the stratosphere.

Climate3_p0296_0001.jpg

Image by Hugh Hunt via Wikimedia Commons.

Research suggests that it might be possible to increase Earth’s albedo and compensate for global warming by adding aerosols to the atmosphere. Mikhail I. Budyko for the first time proposed injecting sulfate aerosols into the atmosphere to create an artificial volcano effect. David W. Keith’s analysis has indicated that about 1.5 to 10.0 million tonnes of sulfate per year would balance the effect of a doubled atmospheric CO2 concentration. The most serious potential side effects of Budyko’s proposal would be alteration of atmospheric chemistry, ozone layer depletion, and whitening of the daytime sky, which would all destabilize Earths ecosystems in ways both predictable and unpredictable.

The enhanced greenhouse effect due to fossil fuel combustion can be reduced by capturing CO2 emissions from industrial power plants and sequestering them. Contemporary climate engineering studies focus on technologies that will extract and compress CO2 from power plants and store them in carbon reservoirs or carbon sinks. The CO2 extraction and capture technologies, which involve precombustion, postcombustion, oxyfuel combustion, and industrial separation (such as natural gas processing and ammonia production), are expensive, require substantial energy, and remain mostly in the research and development phase.

Carbon sinks can be classified as biological, geologic, or oceanic. Carbon from fossil fuel combustion can be sequestered in geologic sinks such as coal, oil, and gas fields and saline aquifers. The Intergovernmental Panel on Climate Change (IPCC) estimates that there is enough capacity worldwide permanently to store as much as 1.1 trillion tonnes of CO2 underground in geological formations. CO2 can be removed biologically from the atmosphere via photosynthesis, afforestation, or changes in farming practices, as well as restoration of phytoplankton by seeding the ocean surface with micronutrients such as nitrates, phosphates, silica, and iron. Conversely, such increased photosynthesis could increase CO2 emissions, deplete oxygen, and trigger climate warming.

The third and greatest carbon sink on Earth is the ocean, which balances atmospheric CO2 levels. About 80% of atmospheric CO2 is absorbed by the oceans on a timescale of about three hundred years. This timescale can be reduced by direct disposal of CO2 in the deep ocean (via pipelines or through dumping from ships) or in geological formations beneath the ocean bed. Accomplishing such sequestration requires a thorough understanding of the feasibility, efficiency, and environmental consequences of such a project.

SIGNIFICANCE FOR CLIMATE CHANGE

Climate engineering appears to be a potential solution to the global warming crisis. However, great caution needs to be taken before attempting any large-scale manipulation of the global climate, as the climate system is extremely complex and chaotic. Moreover, the nations or powers that engage in climate engineering are not necessarily the ones that will suffer the greatest damage should that engineering go awry. Thus, various political and ethical debates arise over whether geoengineering should be considered as a viable option to ameliorate the effects of climate change.

Further Reading

1 

Avanessian, Armen, Werner Boschmann and Karen Sarkesov, eds. Climate Engineering. MIT Press, 2022.

2 

Brovkin, Victor, et al. “Geoengineering Climate by Stratospheric Sulfur Injections: Earth System Vulnerability to Technological Failure.” Climatic Change, September 17, 2008.

3 

Callies, Daniel Edward. Climate Engineering. A Normative Perspective. Lexington Books, 2019.

4 

Gerrard, Michael B. and Tracy Hister, eds. Climate Engineering and the Law. Regulation and Liability for Solar Radiation Management and Carbon Dioxide Removal. Cambridge University Press, 2018.

5 

Hamilton, Clive. Earthmasters: The Dawn of the Age of Climate Engineering. Yale University Press, 2013.

6 

Intergovernmental Panel on Climate Change. Carbon Dioxide Capture and Storage: A Special Report of Working Group III of the Intergovernmental Panel on Climate Change. Edited by Paul Freund et al. Author, 2005.

7 

Keith, David. A Case for Climate Engineering. MIT Press, 2013.

8 

Keith, David W. “Geoengineering and Carbon Management: Is There a Meaningful Distinction?” In Greenhouse Gas Control Technologies: Proceedings of the Fifth International Conference, edited by D. Williams et al. CSIRO, 2001.

9 

Marchetti, Cesare. “On Geoengineering and the CO2 Problem.” Climatic Change 1, no. 1 (March, 1977): 59-68.

10 

Oomen, Jeroen. Imagining Climate Engineering: Dreaming of the Designer Climate. Routledge, 2021.

11 

Rasch, Philip J., Paul J. Crutzen, and Danielle B. Coleman. “Exploring the Geoengineering of Climate Using Stratospheric Sulfate Aerosols: The Role of Particle Size.” Geophysical Research Letters 35 (2008).

12 

Visioni, Daniele. A Climate Engineering Technique for a Warming Planet. Stratospheric Sulfur Injection as a Temporary Solution to Greenhouse Gases Increase. Aracne, 2019.

See also: Anthropogenic Climate Change; Human Behavior Change; Reservoirs, Pools, and Stocks; Sequestration; Sinks; Sulfate Aerosols; Technological Change.

Citation Types

Type
Format
MLA 9th
Nandi, Arpita. "Climate Engineering." Encyclopedia of Climate Change, Third Edition, edited by Richard M. Renneboog, Salem Press, 2022. Salem Online, online.salempress.com/articleDetails.do?articleName=Climate3_0126.
APA 7th
Nandi, A. (2022). Climate engineering. In R. M. Renneboog (Ed.), Encyclopedia of Climate Change, Third Edition. Salem Press. online.salempress.com.
CMOS 17th
Nandi, Arpita. "Climate Engineering." Edited by Richard M. Renneboog. Encyclopedia of Climate Change, Third Edition. Hackensack: Salem Press, 2022. Accessed December 14, 2025. online.salempress.com.