Experts plan to toy with nature, fight warming

But Geoengineering Experiments, Like Using A Giant Mirror To Reflect Sunlight, May Wreak Havoc

    Two years ago this month, in a disused UK airfield, scientists were preparing to undertake one of the more controversial experiments in history. A dirigible balloon would spray 120litres of water droplets into the sky, a miniaturized test for a larger system that would pump out chemical particles to reflect sunlight and, so the scientists hoped, cool the planet. It was to be amomentous day. 
    Geoengineering is the largescale, technological manipulation of the climate (some call it “planet hacking”). But back in 2011, shortly before lift-off, the Stratospheric Particle Injection for Climate Engineering (Spice) team aborted their experiment. There was, they feared, no way of knowing who could use their research, or in what way. 
    Little has changed in practical terms since 2011. Yet, since the end of last month, the prospect of geoengineering has cast a giant shadow over the world of environmental campaigners and climate scientists. On September 27, the Intergovernmental Panel on Climate Change (IPCC), the world’s most respected authority on global warming, acknowledged the need to consider it as a weapon against rising temperatures. And a number of people started to panic. 
    Geoengineering technologies are the stuff of Hollywood disaster movies. Researchers have suggested sending a giant glass sunshade into space to reflect light; the eruption of artificial volcanoes, or spraying of sulphate aerosols into the stratosphere; dissolving mountains and putting remains in the sea; and, filing the ocean with iron filings to stimulate algae blooms. Already, a protest movement of sorts has formed. 
    And the reasons for the concerns go back to the Vietnam War, when US planes seeded clouds in the skies above a strategic pass in Vietnam with silver iodide particles, extending the monsoon season and turning the strategic pass into a bog. In 1977, the Enmod (Environmental Modification Convention) treaty outlawed weather warfare. The IPCC statement has again raised the spectre of weather warfare. 
    Besides, from computer modelling, we know how wrong an answer geoengineering could be. Spraying large amounts of sulphate aerosols into the stratosphere would blur the presence of the sun’s disc. Dumping iron filings into the might kill off large swathes of marine life. 
    But can geoengineering really fight climate change? A look at a few geoengineering experiments might give some idea. Stratospheric aerosols could stop heat from reaching the Earth’s atmosphere by reflecting some of the sun’s rays back into space. Though this would be among the fastest fixes to global warming, itis also among the riskiest. Global weather patterns could be drastically affected. Experts give it a 5/10 score on practicality. 
    As for space reflectors, assembling a giant glass sunshade in space and then firing it into orbit could reflect a small proportion of the sun’s rays, making warming more manageable. But the reflectors would be vulnerable to asteroids, and maintenance would require money. So, the experiment gets a 4/10 on practicality. 
    Ocean fertilization involves dropping iron filings into the ocean to generate blooms of carbon-absorbing plankton. The plankton would take in carbon dioxide, carry it with them as they drift to the ocean floor after death. But it would take a long time for little effect, and could wipe out marine. So, a poor practicality score of 2/10. THE INDEPENDENT

DOUBLE-EDGED SWORD: An artist’s impression of an equipment which, its creator claims, can extract 1,000 times more carbon dioixde a day than a tree