The oceans aren't really blue - thanks to chlorophyll-producing plankton, the ocean has a greenish tint. Now scientists have evidence that making the oceans truly blue could reduce hurricanes and typhoons by up to 70 percent.
If you remove from the ocean all the microscopic phytoplankton, which harvest chlorophyll from sunlight, then the sunlight would penetrate deeper beneath the ocean surface than it can now. This would remove the ocean's greenish tint, and it would impact the formation of hurricanes (and their Pacific counterparts, typhoons) in three crucial ways.
First, the surface water would be much cooler than it is now, which means there's less energy available to feed potential hurricanes. Next, the air circulation above the ocean would change, essentially leading to drier air that is less conducive to the formation of hurricanes. The winds would also increase, which would break up most thunderstorms before they could develop the superstructure necessary for them to become full-blown hurricanes.
Researcher Anand Gnanadesikan of the National Oceanic and Atmospheric Administration ran a series of simulations in which he set the phytoplankton population in certain regions of the Pacific Ocean to zero. Although this change caused an uptick in typhoons along the equator by about 20%, the areas north of the affected region saw a massive 70% drop in typhoons. In real terms, this would cause a few more typhoons to hit the Philippines and Vietnam, but southern China and Japan would see typhoons virtually disappear.
Of course, Gnanadesikan is quick to point out that wiping out all the phytoplankton to reduce hurricanes is probably not a good idea, particularly considering its their chlorophyll production that helps form the foundation of the entire marine ecosystem. Still, the phytoplankton population has been steadily dropping over the last century, and he suggests it's important to consider both the positive and negative impacts of this change, and such a massive decrease in typhoons should definitely be considered a positive impact.