Ocean Plastic

There are dozens of different concepts out there for removing the trillions of pieces of plastic from our oceans. The video below presents an idea that involves two ships that drag a huge net through the water, scooping up everything larger than perhaps a lima bean that’s floating in the top three feet, while allowing fish to escape.

The ships travel at 1.7 mph, and are about 0.2 miles apart. Thus, the net cover 0.34 square miles per hour. The surface of the Earth is 4πr², where r is about 4000 miles, so ~200,000,000 square miles. Our oceans cover about 70% of this, so that leaves us with 140,000,000. To cover them all would require 420,000,000 hours, or 47,945 years.

Fortunately, due to the ocean currents, the plastic tends to agglomerate. The Pacific Gyre Garbage Patch is about the size of the state of Texas, and completing that reduced size would require only 97 years, making such a project feasible with multiple units.