Overcoming global environmental issues

Some technologies are more science fiction than science fact
The hypothetical technology of terraforming (modifying another planet to make it habitable by humans) became a popular idea in the 1970s and early 1980s, because finding a new planet to inhabit seemed a necessity to some in an age when there was much pessimism about the Earth's carrying capacity.
Social revolution and unrest were common in the late 1960s, and photographs of the Earth taken from the Apollo spacecraft showed a tiny, vulnerable planet
More recently, attention has turned to 'engineering' our own planet rather than finding a new one
The 1973 and 1979 oil crises added to the sense of economic gloom
Planetary-scale engineering, referred to as geo-engineering, is seen by some as the way out of the global warming crisis
On a small scale, the $32 million artificial island of Hulhumale in the Maldives, built between 1997 and 2002, is an example of geo-engineering
1. Built 2m above sea level, it is designed to reduce overcrowding on existing islands, but also to replace them as they are inundated by the sea-level rise generated by global warming
Geo-engineering is perhaps the ultimate technological fix, as it seeks to control the nature of the entire planet
Sulphur Aerosols
1. Sulphate particles scattered in the stratosphere from balloons or planes block incoming solar radiation and cool the planet
2. A similar effect occurs naturally after a major volcanic eruption
3. Estimated cost - $50 billion every 2 years
4. Sulphur could damage the ozone layer
5. Polluting the atmosphere to solve a problem caused by pollution can be seen as unethical
6. Acid rain could occur
7. Global rainfall patterns might be disrupted
Space Mirrors
1. Launching giant mirrors into geo-stationary orbit to reflect solar radiation away from Earth, creating a cooling effect
2. A Russian attempt in 1999 failed
3. The technology for huge lightweight mirrors needs to be developed
4. Models suggest that this would create warmer high latitudes and cooler tropics - not a pre-industrial climate
5. Costs estimates exceed $1 trillion
Ocean Fetillisation
1. Iron particles added to oceans to encourage plankton, which sequesters carbon dioxide as it grows
2. When plankton dies it sinks to the ocean flood
3. The company Planktos began trials in 2007 but abandoned them a year later
4. The UN agreed a moratorium on this technology in 2008, fearing biodiversity would be harmed
5. Oceans could become acidified by the sequestered carbon dioxide
6. It could cost $5 per tonne of carbon sequestered
7. Uo to 6 billion tonnes per year would need to be sequestered at 2008 emission levels
Synthetic Trees
1. The 'trees', designed by Klaus Lackner, are intended to sequester 90,000 tonnes of carbon dioxide per year
2. They would use sodium hydroxide to capture carbon directly from the atmosphere, which would need to be buried
3. Hundreds of thousands of trees would be needed, taking up large amounts of space
4. Costs are estimated at $30 per tonne of carbon dioxide
5. Trees would need to be powered
6. Deep burial sites for the captured carbon dioxide need to be found

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Overcoming global environmental issues

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	Erstellt von Jodie Goodacre vor fast 11 Jahre