Geoengineering is a branch of science which uses technology to change the Earth's environment mainly focused on mitigating the effects of global warming. One of the fundamental parts of planetary engineering is terraforming, which involves altering the surface of a planet to give it more Earth-like features.
Why should I be aware of this?
- As the difficulty of reducing greenhouse gas emissions is becoming more and more difficult to ignore, geoengineering is slowly emerging as an option of last resort.
- Though global warming is among the major focus areas, other issues may come to be addressed by geoengineering in time.
- As geoengineering is a radical branch of science it is feared, even among a part of the scientific community, that it may harm as much as help, as the balance of life on Earth is still not perfectly understood.
All about Geoengineering
A number of geoengineering proposals do the rounds in mainstream media. Examples range from using orbital mirrors to bounce sunlight back into space, fertilising the world's oceans with iron to increase their absorption of carbon and painting the roofs of buildings white to increase solar reflection (similar to polar ice caps). Fertilizing the world's oceans involves stimulating algae production to scrub carbon dioxide from the air.
Some of the schemes which have been proposed by geoengineers are quite radical, and they would require global discussion and cooperation before implementation.
Discussions remain at academic level
At present discussion on geoengineering is mainly at an academic level and has not been taken up as a political agenda. However, with increased global warming it may become a public debate in the near future.
Plans have remained in the drawing board as changes to the Earth's environment would obviously impact all life on Earth, for better or for worse, and some scientists would prefer to see less drastic approaches to human-caused climate change and environmental problems.
In spite of being pushed to the fringe for decades, geoengineering ideas never died. However, certain recent developments have brought them back into the mainstream:
- First, despite years of talk and international treaties, CO2 emissions are rising faster than the worst-case scenario envisioned as recently as 2007 by the Intergovernmental Panel on Climate Change
- Second, ice is melting faster than ever at the poles, suggesting that climate might be closer to the brink—or to a tipping point, in the current vernacular—than anyone had thought.
Trigger global cooling
One of the most discussed is an intentional darkening of the Earth's atmosphere, to trigger global cooling.
The proposal is to inject several million tons of sulfur dioxide (SO2) a year into the stratosphere. There it would react with oxygen, water and other molecules to form minute sulfate droplets made up of water, sulfuric acid (H2SO4) and whatever dust, salt or other particles onto which the acid and water condense. Clouds of sulfate droplets would scatter sunlight, making sunsets redder, the sky paler and the earth’s surface, on average, cooler.
This has been proved by the results of the 1991 volcanic eruption of Mount Pinatubo in the Philippines which put 20 million tons of SO2 into the stratosphere. It had cooled the earth by nearly one degree Fahrenheit for about a year.
To determine the global consequences of geoengineering projects, extensive tests are needed. However, it is not becoming to conduct controlled geo-engineering experiments and reversing geo-engineering projects that went wrong would be extremely difficult and costly.
A simple and probable test could be monitoring how the atmosphere responds to volcanic eruptions, a process of nature that is similar to some proposed geo-engineering solutions. Volcanic eruptions are known to have a cooling effect on the globe after projecting large amounts of sulphur dioxide into the atmosphere.
The risks of replicating such a process could result in acid rain and damage to the ozone layer, and a debate is yet to be had as to whether this is an acceptable consequence to halting global warming of over 3 degrees.
At present, global emissions of greenhouse gases are still rising by 2% to 3% a year. If that continues, average world temperatures are projected to rise by as much as 5.5C by 2100. 
- What is Geoengineering?
- ↑ TIMES ONLINE