It’s been an interesting few weeks. UN meetings, talks with major film and television networks about filming my nonprofit’s expeditions as we sail around the world studying plastic in our oceans. Lately, I’ve been obsessed with the concept of global pollution in terms of scale. The scale of problems is often so big that the numbers cease to have meaning for the vast majority of people because they’re incomprehensibly large. So how do you do? Well, the answer is, you geek out. You run statistics and you do the math. So that’s what I did all weekend.
It’s no secret by now that I’m all about reducing synthetics in our lives. I try like hell to avoid plastics, even when I travel where water is sketchy. I’ll be reporting on a portable water radiating device I’ve obtained for my surf trip to Mexico in a few weeks – yup, I’m going to attempt to drink tap water to avoid plastic bottles – but why? Why are you so pathologically devoted to plastic pollution Stiv? Well, we all know there is garbage in the ocean that collects in places, and stays there forever. But we don’t know how much, because the amount is hard to noodle on. Here’s a an attempt to paint a picture for you.
The Scale of Global Plastic Pollution
Sailing across North Atlantic taught me something that all oceanographers know, but don’t necessarily say: the ocean is big and running the numbers on how much garbage is out there, proves to be a difficult task.
According to one prominent ocean scientist, SEA’s Giora Proskurowski, plastic is extremely diffuse and calculating its density isn’t very easy. Giora’s data states that concentration in The Atlantic gyre is about 50,000 .1g pieces per square kilometer on the surface. If we apply big math to that simply for the sake of getting an idea of scale, we get five kilograms per square kilometer or roughly 11-pounds per square kilometer on the surface. There are 316 million square kilometers of ocean surface. This makes for about 3.5-billion pounds of degraded plastic fragments fewer than 5mm in length on the surface of the ocean worldwide. Again, this is an extremely conservative estimate, extrapolating from a local data set to show the scale in the world. Giora’s work, for example, shows that plastic doesn’t just exist on the surface, it gets stratified within the water column, close to 90-feet down (not to mention all the types of plastic that sink, too, which is about half of the types manufactured). This estimate doesn’t include all the big pieces you find in various garbage patches within the gyres, but we’ll leave that weight out for now.
So, for the purposes of argument, let’s say that for each of those 90-feet of stratification, there is roughly the same weight per foot. Now we’re up to 315 billion pounds in the ocean. For comparison, The Gulf Spill is spewing roughly 2.5-million pounds of oil per day.
Cost of Cleanup, Hypothetical
A supertanker’s dead weight (amount of weight it can carry) is 500 million pounds. That would mean that to clean the ocean, you’d need to fill 630 oil supertankers to the brim at a cost of about $56,000 per each a day to charter (United Nations Conference on Trade and Development). Therefore, to cleanup the gyres (assuming there is actually technology out there to do it which as of today, nothing has been proven to work) we’re looking at a cost of at least about $35 million a day or roughly $13 billion a year. And about 17 percent of all the oil tankers in service in the world would have to be full-time devoted to cleaning it up.
Now let’s talk about the scale of waste. As of 1992, the world (5.5 billion people, which today has grown to seven billion) dumped 14 billion pounds of garbage in the ocean each year, with over half (at the very least) being synthetics. If we apply this statistic over 40 years – the plastics era in the limelight – we get a very similar number to the 315 billion pound number stated before of overall plastics in the ocean. Worldwide, we’re looking at one to three percent recycling rates on plastic, a number based on an industry that is governed by supply and demand. The plastics industry produces 250 billion pounds of virgin raw plastic pellets per year. Okay, so now we at least have an ‘some idea’ of what we’re dealing with.
Great! Now that I feel sick to my stomach, what can I do?
One American’s ‘garbage in the ocean’ footprint is about 600 (as of 1992) pounds annually. If you want to know precisely what your plastics in the ocean footprint is do a simple experiment: throw all your waste in the same bin for a week. Separate organic materials and synthetics. Determine the percentage of synthetics and apply that percentage to that 600 pound number, and you’ll know roughly how much damage your lifestyle causes on the ocean in terms of weight. Now, take some action. Look at your own waste stream and see which items you can avoid all together or replace with reusable alternatives. I promise you, you’ll be surprised at how much difference you can personally make. Now go to it!