Monday, July 27, 2009

Bill Gates takes on hurricanes. And: A Quiet Tornado Season

Two months into a very quiet hurricane season, and following a quiet tornado season*, we are coming into the two most dangerous months for hurricanes. Until we get, at minimum, a tropical storm, I'll be posting on ancillary topics. From Dr. Jeff Masters' WunderBlog:
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:

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....

*From NOAA's Storm Prediction Center, through July 25:

Annual Running Totals (Updated Frequently)
Tornado Reports | Hail Reports | Wind Reports
Annual Tornado Running Totals
Plot of the annual running total of tornado reports compared to inflation adjusted values. (Click on graph for a full description.)

Annual Tornado Trends