planetary engineering
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 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 evidence that humans can cause change on a global scale.
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.
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]. 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, while the scientific community is mostly in agreement over 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]
Geoengineering is the name given to large scale planning projects aiming to counteract or reduce the effects of planetary change. For example, some have proposed putting large mirrors in orbit which would modify the insolation received by Earth - either increasing or decreasing it, as the need arises. Other examples which have been seriously considered include: large-scale sequestration of CO2 inside geological formations or ocean sediment, the modification of Earth's albedo with reflective or absorptive materials spread over portions of its surface, the alteration of rainfall patterns through the creation of artificial seas, and the depositing of iron in the ocean to encourage algae growth. To date, none of these proposals has been implemented on truly a planetary scale.
Criticisms
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 affects 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. 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 preserve human life. This disregard for the overall health of Earth's ecosystems and natural environments is an affront to proponents of sustainable development.
See also
External links
- Geoengineering: A Climate Change Manhattan Project
- UC Berkeley's GeoEngineering program
- Caldeira lab
- 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.
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.
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