Superfreakonomics_ global cooling, patri - Steven D. Levitt [72]
But, one might be tempted to ask, doesn’t this constitute playing with Mother Nature?
“Of course it’s playing with Mother Nature!” Nathan cackles. “You say that like it’s a bad thing!”
Indeed, if we hadn’t played with Mother Nature by using ammonium nitrate to raise our crop yields, many readers of this book probably wouldn’t exist today. (Or they would at least be too busy to read, spending all day scrounging for roots and berries.) Stopping polio was also a form of playing with Mother Nature. As are the levees we use to control hurricane flooding—even if, as in Hurricane Katrina, they sometimes fail.
The anti-hurricane solution Nathan proposes is so simple that a Boy Scout might have dreamt it up (a very clever one, at least). It can be built with materials bought at a Home Depot, or maybe even filched from the dump.
“The trick is to modify the surface temperature of the water,” Nathan says. “Now the interesting thing is that the surface layer of warm water is very thin, often less than 100 feet. And right beneath it is a bulk of very cold water. If you’re skin-diving in many of these areas, you can feel the huge difference.”
The warm surface layer is lighter than the cold water beneath, and therefore stays on the surface. “So what we need to do is fix that,” he says.
It is a tantalizing puzzle—all that cold water, trillions upon trillions of gallons, lying just beneath the warm surface and yet impotent to defuse the potential disaster.
But Nathan has a solution. It is basically “an inner tube with a skirt,” he says with a laugh. That is, a large floating ring, anywhere from thirty to three hundred feet across, with a long flexible cylinder affixed to the inside. The ring might be made from old truck tires, filled with foamed concrete and lashed together with steel cable. The cylinder, extending perhaps six hundred feet deep into the ocean, could be fashioned from polyethylene, aka the plastic used in shopping bags.
“That’s it!” Nathan crows.
How does it work? Imagine one of these skirted inner tubes—a giant, funky, man-made jellyfish—floating in the ocean. As a warm wave splashes over the top, the water level inside the ring rises until it is higher than the surrounding ocean. “When you have water elevated above the surface in a tube like that,” Nathan explains, “it’s called ‘hydraulic head.’”
Hydraulic head is a force, created by the energy put into the waves by wind. This force would push the warm surface water down into the long plastic cylinder, ultimately flushing it out at the bottom, far beneath the surface. As long as the waves keep coming—and they always do—the hydraulic head’s force would keep pushing surface water into the cooler depths, which inevitably lowers the ocean’s surface temperature. The process is low-impact, non-polluting, and slow: a molecule of warm surface water would take about three hours to be flushed out the bottom of the plastic cylinder.
Now imagine deploying these floats en masse in the patches of ocean where hurricanes grow. Nathan envisions “a picket fence” of them between Cuba and the Yucatán and another skein off the southeastern seaboard of the United States. They’d also be valuable in the South China Sea and in the Coral Sea off the coast of Australia. How many would be needed? Depending on their size, a few thousand floats might be able to stop hurricanes in the Caribbean and the Gulf of Mexico.
A simple throwaway version of this contraption could be built for roughly $100 apiece, although the larger costs would come in towing and anchoring the floats. There’s also the possibility of more