Flash scheme: One of the ideas involves placing giant mirrors in space to reflect the Sun's rays away from Earth.
Credit: iStockphoto
Some of the stranger schemes proposed to tackle global warming were knocked down by the U.N.'s Intergovernmental Panel on Climate Change when it met in Thailand, last year (see, Oddball global warming schemes rejected).
Due to slow political progress, though, and panic about the pace and scale of warming now being reported, some of these quick fixes may soon be back in favour (see, Wacky climate solutions back on table).
Here, we share seven bold and unconventional solutions put forward to solve the climate change conundrum.
GIGANTIC MIRRORS: Six enormous tilting mirrors, each up to 2,000-kilometres-wide, or tens of thousands of foil-covered 'flying saucers' could be launched into space; either way experts at the University of Arizona in Tuscon, U.S., estimate we could deflect two per cent of the Sun's rays. That's enough to mitigate a year's worth of human-generated carbon dioxide emissions — and at just U.S.$3 trillion, it's a steal.
SYNTHETIC TREES: Not so much trees as 30-metre-tall, metal, carbon dioxide guzzlers, they would devour 90,000 tonnes of the greenhouse gas each year. Devised by scientists at Columbia University, New York, they work by reacting the gas with sodium hydroxide before converting it to liquid to be stored underground. They may be uglier than real trees, but the real challenge is finding a way to power them without generating yet more greenhouse gases.
ORBITING DUST SHIELD: Dust would be sent into orbit around the Earth by strategically vaporising a comet, perhaps using a nuclear detonation. Proposed by researchers at Iowa State University in Ames, the dust cloud would eclipse the Sun for several hours each month, filtering out about one per cent of solar radiation. Blowing up comets is a risky business though, in anyone's books, especially when done relatively close to the Earth.
ARTIFICIAL VOLCANOES: When Mount Pinatubo in the Philippines erupted violently in 1991, it pumped millions of tons of sulphur dioxide into the atmosphere, which reduced global temperatures by 0.5°C the next year. Drawing upon that as inspiration, chemists at the Max Planck Institute in Mainz, Germany, suggest replicating the effect by 'seeding' the atmosphere with sulphates to reflect light. Then again, it might also cause a flood of acid rain (see, Fake volcanoes could combat global warming).
MAN-MADE CLOUDS: Under this proposal, a fleet of 1,000 specially-designed ships would patrol the oceans, pumping out seawater vapour to fluff up clouds. Marine engineers at the University of Edinburgh in Scotland calculate that the clouds could reflect up to two per cent of sunlight. If it works, this innovation could effectively export the trademark Scottish grey skies worldwide.
WHITEWASH: Ice and snow reflect up to 80 per cent of sunlight hitting the poles. Climate experts at the University of New South Wales in Sydney, Australia, argue that by painting roofs and roads white, and covering everything from deserts to oceans in reflective foil we could deflect sunlight. Cities would certainly look less colourful from the skies, and we'd probably all need to wear sunglasses more often.
ALGAL BLOOMS: Encouraging a population explosion of algae with iron or nitrogen fertiliser might sound unimpressive, but phytoplankton already absorbs half of the 29 billion tonnes of carbon dioxide produced by humans each year, in effect locking it up at the bottom of the oceans when they die. By feeding the masses with some iron ore dust, scientists at Moss Landing Marine Laboratories, California, hope to boost plankton numbers and draw more carbon out of the atmosphere. However, it could have unpredictable effects on the complex oceanic food chain.
Liz Williams is a science writer based in Perth, WA.
