Bill Gates thinks big.  

His charitable foundation has poured $1 billion into the fight against that great scourge of humankind, malaria, resulting in the creation of a new vaccine that is 100% effective in mice, and is now headed towards trials in humans. If successful, Gates' efforts have the potential to save millions of lives. Gates has also turned his attention to another great scourge of humankind, the hurricane. In a 2008 patent filing that recently came to light, Bill Gates and his friends presented a scheme for reducing the strength of hurricanes by cooling sea surface temperatures, using a fleet of ships that bring up cold water from the depths. Can Gates really pull this off? I don't think so. The obstacles are fourfold: technical, financial, environmental, and legal.

Figure 1. A diagram from a 2008 Bill Gates patent filing, depicting an array of hurricane-control vessels in the Gulf of Mexico. Image credit: techflash.com.

Technical issues

While modification of hurricanes is theoretically possible, the scale of the undertaking is truly enormous. A fleet of dozens or hundreds of ships spanning a huge swath of ocean would be required, and these ships would have to be able to withstand the 50-foot waves and 160 mph winds a major Category 5 hurricane could deliver. As I discussed when a similar scheme was proposed in 2006 by Atmocean, Inc., it is not clear how long the cold water pumped to the surface will stay there--the cold water pumped to the surface is more dense than the water beneath it, and so will tend to sink, allowing warmer water beneath to replace it and warm the surface waters again. Modeling studies and field studies are needed to determine if the cold water can stay at the surface long enough to significantly affect a hurricane. Furthermore, simply cooling the ocean may have no effect on a hurricane, if the storm is in a favorable upper-atmospheric environment with low wind shear.

Financial issues

Any hurricane modification effort is going to be tremendously expensive. The cost of the array of cooling pumps proposed by Atmocean in 2006 for the Gulf of Mexico was pegged at $2.4 billion. Gates' scheme would have a similar cost. He proposes paying for it through government funding and the sale of insurance policies in hurricane-prone areas.

Environmental issues

A large change to the ocean temperatures over a wide area of ocean is bound to have significant--and unknown--impacts on fisheries and wildlife. Regional weather patterns may also be affected, intensifying droughts or bringing heavy rains and flooding.

Legal issues

Hurricanes naturally make sudden unpredictable course shifts, and the hurricane modification efforts are also capable of causing track shifts in a storm. Residents on the coast hit by the modified storm will want to sue, and there will be many lawyers more than happy to take their case. Gates would have to get special legislation passed to protect his company from lawsuits, such Congress passed for the gun industry in 2006.

Summary

In summary, we simply don't know enough about hurricanes yet to safely engage in modifying them. A lot more research is needed before we should spend the huge sums needed to attempt hurricane modification. The Department of Homeland Security has a $1 million research effort going that will attempt to answer some of these questions, called HURRMIT (The Identification and Testing of Hurricane Mitigation Hypotheses). The HURRMIT program is evaluating the potential of a number of hurricane modification techniques, including:

• Seeding with tiny hygroscopic aerosols to suppress warm rain
• Seeding with radiation-absorbing aerosols (i.e., carbon black) at the storm periphery
• Seeding with radiation-absorbing aerosols (i.e., carbon black) at storm top
• Pumping cool water from the depths to the ocean surface in front of the hurricane

Frankly, I'm dubious that the money being spent on HURRMIT is worth it, given the four huge obstacles to hurricane modification I presented above.

However, the research may provide some new insights into hurricane intensification that we don't have now. In closing, I'll present the proposal one reader of an New Orleans online newspaper had:

Bill Gates should just have one of his employees write an ActiveX Script for Google maps so we can just highlight the hurricane, right click on it, then select delete. Or maybe just cut and paste it farther out into the Atlantic Ocean.

Courtesy of Dr. Jeff Masters of WeatherUnderground.com