Planetary engineering
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Planetary engineering is the application of technology for the purpose of influencing the global properties of a planet.[1] The goal of this theoretical task is usually to make other worlds habitable for life.
Perhaps the best-known type of planetary engineering is terraforming, by which a planet's surface conditions are altered to be more like those of Earth. Other terms used for particular types of planetary engineering include caeliforming,[citation needed] for the creation of an Earth-like atmosphere, and ecopoiesis for the introduction of an ecology to a lifeless environment. Planetary engineering is largely the realm of science fiction at present, although some types of climate change on Earth are recent evidence that humans can cause change on a global scale.
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[edit] Terraforming
Terraforming is the hypothetical process of deliberately modifying the atmosphere, temperature, or ecology of a planet, moon, or other body to be similar to those of Earth in order to make it habitable by humans.
[edit] Geoengineering
Geoengineering is the deliberate modification of Earth's environment on a large scale "to suit human needs and promote habitability". [2] Others define it more narrowly as focusing only on the mineralogy and hydrology of the Earth.[3] The term geoengineering is distinct from accidental anthropogenic climate change.
As human populations grow and technology spreads, measurable changes in the Earth are becoming more apparent. Anthropogenic land use, accelerated since the industrial revolution, have led to the alteration of between one-third and one-half of the Earth's land surface. Levels of atmospheric CO2 have increased by approximately 30 percent over the last two centuries. More atmospheric nitrogen is fixed by humanity than by all natural terrestrial sources combined. And, more than half of all accessible surface fresh water is put to use by humans.[4]
Records indicate that surface temperatures have risen by more than half a degree Celsius (one degree Fahrenheit) within the last 50 years. Sea surface temperatures (SST) have also risen during the last 30 years by a comparable amount.[5]. While there is still political debate over the notion that these changes in Earth's climate are the accidental result of human civilization through the industrial emission of greenhouse gases, the scientific community is almost entirely in agreement about the science of global warming. According to most climate models, climate change may result in altered precipitation patterns and the increased frequency and severity of extreme weather around the world.[6]
Much proposed geoengineering is a reaction to human-induced global warming. Although many geo-engineering projects have been proposed (see below), large-scale CO2-storage through tree-plantations is the only serious, globally accepted means to decrease greenhouse gases. In addition, it is also the only scheme being undertaken on a large (or planetary) scale.
[edit] Proposed projects
Several geo-engineering projects have been proposed. The documentaries Five ways to save the world and La temperature grimpe[7] describe many of the most notable projects. Important projects include:
- Mirrors in space: proposed by Roger Angel with the purpose to deflect a percentage of solar sunlight into space, using mirrors floating around the earth in orbit.[8]
- Stratosphere sulfur-spraying: proposed by Paul Crutzen with the purpose to modify the earth's albedo with reflective or absorptive materials spread over portions of its surface.[8]
- Phytoplankton: proposed by Ian Jones with the purpose to fertilize the ocean with urea, a nitrogen rich substance, to encourage phytoplankton growth.[8]
- Cloud-seeding: proposed by John Latham and Stephen Salter with the purpose to spray seawater in the atmosphere to increase the reflectiveness of clouds.[8]
- Artificial Trees: proposed by Klaus Lackner with the purpose to suck carbon out of the atmosphere.[8]
[edit] Criticisms
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While many proposals have been considered, none have been implemented on a large scale. Many members of the scientific and technical communities fear that the full effects of various geoengineering schemes are not fully understood. The failure of the ambitious Biosphere 2 facility is one example of a complex project that was unsuccessful because scientists still have a limited understanding of how earth systems work together; the implications for a failed project of global scale are frightening, and as a result policy-makers are hesitant to embrace various geoengineering schemes for combating the effects of global warming.
Other criticism comes from those who see geoengineering projects as reacting to the symptoms of global warming rather than addressing the real causes of climate change. Because geoengineering is a form of controlling the risks associated with global warming, it leads to a moral hazard problem. The problem is that knowledge that geoengineering is possible could lead to climate impacts seeming less fearsome, which could in turn lead to a weaker commitment to reducing greenhouse gas emissions.[9] It could be argued that pursing geoengineering solutions sends the message that humans can continue to live out of harmony with the Earth as long as we have enough clever technological solutions to preserve human life. This disregard for the overall health of Earth's ecosystems and natural environments is an affront to proponents of sustainable development.
Furthermore, geoengineering opens up various political and economic issues. David Keith argues that the cost of geoengineering the Earth is within the realm of small countries, large corporations, or even very wealthy individuals. This effectively eliminates any control over who gets to decide when to cool the Earth and how often this should be done. [10]
However, it could also be argued that more conservative use of resources is not enough to mitigate global warming. Even if all greenhouse emissions suddenly came to a complete halt, the climate would continue to warm well into the next century due to the residual effect of greenhouse gases. Conservation of resources and reduction of greenhouse emissions, used in conjunction with geoengineering, could be considered the best option by some.
[edit] See also
[edit] External links
- Geoengineering: A Climate Change Manhattan Project (Stanford Envtl. Law Journal
- UC Berkeley's GeoEngineering program
- Geo-engineering blogspot; website describing all current methods/proposals done to revert climate change by geo-engineering
- 5 ways to save the earth; documentairy about geo-engineering
- Caldeira labat the Carnegie Institution for Science
- ClimateShield - Lifeboat Foundation ClimateShield
- Guns and sunshades to rescue climate BBC News
- Climate Engineering Is Doable, as Long as We Never Stop Wired Magazine
- Morton, Oliver (10 May 2007). "Climate change: Is this what it takes to save the world?". Nature 447: 132-136. doi:10.1038/447132a.
- 10 Ideas That Are Changing The World: 6.Geoengineering Time Magazine
[edit] References
- ^ Fogg, Martyn J. (1995). Terraforming: Engineering Planetary Environments. Warrendale, PA: SAE International.
- ^ "a controversial field known as geoengineering, which means rearranging the Earth's environment on a large scale to suit human needs and promote habitability" How to Cool a Planet (Maybe) New York Times - June 27, 2006}}
- ^ UC Berkeley Department of Civil and Environmental Engineering. Retrieved on 2007-05-05.
- ^ Vitousek, P.M.; Mooney, H.A., Lubchenco, J., Melillo, J.M. (1997). "Human Domination of Earth's Ecosystems". Science 277: 5325.
- ^ Sheppard, C. R.; Spalding M., Bradshaw C., Wilson S. (Feb 2002). "Erosion vs. recovery of coral reefs after 1998 El Niño: Chagos reefs, Indian Ocean". Ambio 31 (1): 40-8.
- ^ Intergovernmental Panel on Climate Change. Retrieved on 2006-05-26.
- ^ La temperature grimpe-documentary
- ^ a b c d e Five ways to save the world-overview
- ^ David Keith. "A surprising idea for solving climate change (lecture at TED conference)". Retrieved on 2008-04-06.
- ^ David Keith. "Engineering the Planet" "3-4,8". Retrieved on 2008-04-08.
