September 8, 2007
To save the planet from global warming − a looming catastrophe many believe we can no longer prevent − could require that China stop building the equivalent of a new 1000 megawatt coal plant every five days, and India the same equivalent every two weeks. It could also require that the rest of the developing world slows its economic growth, for the good of humanity. And it could require us, in the rich countries, to dramatically curtail our air and auto travel, and other greenhouse gas producing activities, even if it means plunging ourselves into recession if not depression.
Or, stopping global warming could require sailing a fleet of 50 globe-cooling yachts on the high seas. To Stephen Salter, emeritus professor of engineering design at the University of Edinburgh and the inventor of the cool yachts, there is but one credible course to take, and informed scientists know it. Earlier this week at a climate debate sponsored by the Royal Meteorological Society, “I asked for a show of hands about whether official proposals for CO2 reductions could do enough to stop global warming in time,” he explained. “Not one of 300 people with professional interest in the field raised a hand.”
In contrast to the utter futility of attempting to quickly refashion the global economy into a carbon-lean machine, Prof. Salter’s machine provides realistic hope. Low-level stratocumulus clouds blanket about one-quarter of the world’s ocean surface, cooling the waters below by reflecting the sun’s rays back into space. Brightening those clouds with sea salt to increase their reflectivity by a mere 3%, atmospheric scientists calculate, would provide sufficient additional cooling to counteract the warming effect caused by increased CO2 in the atmosphere. The sea salt would be delivered via fine sprays of ocean waters from Prof. Salter’s yachts.
The amount of salt water required to cool the planet is surprisingly small − 50 ships, each pumping salt water at the rate of 10 kilograms per second to produce tiny droplets, could suffice. The tiny droplets evaporate to leave salt residues, which are then distributed by the winds to seed the clouds. In an attempt to waste not a droplet, the yachts − unmanned and controlled by satellite − would continually roam the oceans, positioning themselves where cloud conditions were optimal and the need for cooling was greatest.
The scheme seems fanciful and implausible, but not to many scientists immersed in the climate change field. Eminent scientist John Latham at the U.S. National Center for Atmospheric Research, who first proposed cloud-seeding to cool the planet in a 1990 Nature article, is Prof. Salter’s enthusiastic collaborator in the venture. Scientists at NASA, Brookhaven, the U.K.’s Royal Meteorological Society and other prominent agencies likewise see promise in the cloud-seeding concept. It is Prof. Salter’s own track record, however, that dispels any notion that the cool yachts are more fantasy than fantastic.
He is known as one of Scotland’s greatest inventors, and as the father of modern wave energy technology, which is now being introduced in countries throughout Europe. His digital hydraulics may revolutionize windmills and automobiles. Among his many other presciences, in 1968 he invented the touch computer screen. The wind-powered yacht with its odd rotor sails is not his, however, and is also not new. This 1920s invention, by Germany’s Anton Flettner, was an unusually stable commercial ship that crossed the Atlantic, out-sailing normal schooners under moderate to heavy winds.
Prof. Salter’s cool yachts do have one major design flaw: They promise to save the planet for a pittance, and without making humans pay a dear price for their profligate ways. Fifty ships a year, built at a cost of some $400-million to $500-million, would remove the increased warming now attributed to all the fossil fuel burning. They would also provide the time required for an orderly transition to economies based on renewable fuels − the passion of Prof. Salter’s professional life.
For reasons that would be unfathomable to many, environmentalists at Greenpeace and elsewhere have emerged as critics of the cool yachts, dismissing them out of hand as wacky inventions “that in all likelihood would come to nothing” and saying: “We’re looking for reductions in the use of fossil fuels rather than these technologies.”
A more important critic, because it holds the purse strings, is the U.K. Environment Ministry, responsible for abating global warming. It has been doing its best to trim Prof. Salter’s sails. The technology that Prof. Salter proposes is not yet soundly proven, it says, refusing to provide the $5-million in funds required to soundly prove it. The technology could lead to increased rainfall over the oceans, it says, without saying why this poses a problem comparable to that of global warming. The EU has committed to carbon trading as a means of countering global warming, it says, without acknowledging that carbon trading has failed to slow the increase in carbon dioxide. Marine animals could be affected by the technology, it says, as if the consequences of global warming would not affect them. An environmental assessment of the effects of spraying salt water into the air is required, it says, while dismissing Prof. Salter’s detailed proposal for conducting one.
The public might not like the yachts, the Environment Ministry also says, when it really fears that the public might like them too much.
Lawrence Solomon is executive director of Energy Probe and the Urban Renaissance Institute.
CV OF A DENIER
Prof. Stephen Salter, emeritus professor of engineering design at the School of Engineering and Electronics at the University of Edinburgh, is “one of the finest engineers that Scotland has produced,” according to Alex Salmond, Scotland’s First Minister. Prof. Salter is an authority on energy matters in general and renewable energy in particular. He is best known for his pioneering work to harness wave energy, which he begun in the 1970s in response to the OPEC oil crisis. His invention, Salter’s Duck, is the machine against which all others are measured. In small-scale controlled tests, the Duck can stop 90% of wave motion and can convert 90% of that to electricity. Cambridge-trained, Prof. Salter is a fellow of the Royal Society of Edinburgh, the inventor of numerous technologies, and the author or co-author of numerous papers.