I'm not an environmentalist, marine biologist, petroleum engineer, or any other of the myriad professionals that has something to say about the science of the plastic patches in each of the five major gyres of the world's oceans. Therefore, I will embed the Ted Talk from Capt. Charles Moore, the discoverer of the Pacific Plastic Patch, to explain the basics.
Now, what does an economist have to say about this terrifying threat to the environment? Plenty. These plastic patches are what economists would call a negative externality, an effect derived from an economic action that does not accrue to the actor and hence is ignored when an action is taken. We all use and throw away plastic on a daily basis, but we are generally shielded from paying the full costs of disposal. None of us are held responsible when our waste gets into the ocean. The result, as economic theory tells us, is that we use too much plastic for too many things. If we as consumers and producers had to consider the costs of plastic disposal, our decisions would likely be drastically different.
In order to remedy this problem, we would need to devise a system that gives plastic users accurate signals of the true costs of their actions to the environment and human society. I'm reasonably sure this is impossible for a number of reasons. First, we can't tell how much this pollution bothers other people. In other words, interpersonal comparisons of utility aren't possible. Furthermore, even if aggregating damages across people were possible, we still would have no way of reckoning with the costs to the unborn. The plastic will stay in the ocean until something is designed or evolves that can digest it, or we figure out a viable way to remove it (and keep it from returning).
Since a clean, healthy ocean filled with wildlife isn't traded on a market, we would also have to deal with the related inability to price the damage. If we had market prices for these things, we could charge disposal fees in line with damages without resorting to metaphysical concepts like utility (although the unborn would still be ignored). A cost-based approach is out of reach as well, since we cannot determine the cost of a clean-up effort yet to be devised. Trolling nets (so I understand) could collect much of the plastic but would also collect the base of the food chain and kill off the wildlife that remains in these gyres.
To my mind, that leaves only one course of action, one I happen to loathe: making laws governing the use of plastic in production and the methods and fees for disposal of used plastic items. This proposal has an infinitesimal chance of getting the cost-benefit analysis correct, so I can only argue here that movements in the right direction (of increasing disposal costs accruing to manufacturers and consumers) is better than nothing, especially starting from the position of rampant abuse of this material.
If we create these laws (and other countries follow suit, another seemingly irresolvable problem), we might be able to alleviate some of the destruction from plastic waste. For one thing, we would be much less disposed to use plastic for disposable items. Beyond the obvious items like disposable lighters and pens (I'm looking at you, Bic.), there are many more items meant for temporary use that are made from plastics. Particularly egregious examples that come to mind are shopping bags, the packaging film surrounding almost every durable or semi-durable consumer item on the market, and the containers for personal items like deodorant, sunscreen, etc. None of these items are recyclable in the city I live in. Only very specific forms of plastic (like bottles) are allowed in the recycling bin.
I would love to hear more examples from readers. Even vacuum cleaners and other electronic items wear out and become obsolete, so we either need to find other ways to construct these products or get much better at reusing the materials once the item is worn out. I presume we could use other materials for these purposes, and we could redesign other plastic items, like the lighters and pens mentioned previously, to be reusable ad infinitum.
I do not claim to have all the answers, so I look forward to suggestions from people with a more refined understanding of the science and/or more creativity in their approach. The only thing I'm absolutely convinced of is that we have a huge problem staring us in the face that we are largely ignoring while debating endlessly whether the globe is really warming and whether humans have anything to do with it. There is more than one potentially catastrophic man-made environmental disaster on the horizon.