When looking at the scale of ocean plastic pollution, one number keeps coming up: 8 million tonnes. This is the amount of plastic that is estimated to enter our oceans every year. 8 million tonnes sounds like a lot, but just how much is pretty hard to fathom. How can we even begin to visualise 8 million tonnes of plastic without any point of reference? It’s frequently compared to dumping one garbage truck full of plastic into the ocean every minute of the year. That would be 525,600 garbage trucks. That definitely helps give an impression of the scale of the problem, but 525,600 trucks is just another large number. Try visualising that and your head will start to hurt. In this series of blogs then, I'm going to try to give a more comprehensible picture of those 8 million tonnes of ocean plastic.
My starting point for our first look at 8 million tonnes of plastic comes from the animated film WALL-E. Set in 2805, WALL-E portrays an Earth choked by rubbish and abandoned by humans. In the opening sequence, as we zoom in from outer space and into Earth’s polluted atmosphere, we see a world in which skyscrapers are now overshadowed by looming towers of rubbish. It's a powerful image of humanity's problem with over-consumption and waste. For copyright reasons I'll leave out still images from the film, but for anyone interested I recommend giving it a watch. We soon find out that these towers have been constructed by a fleet of robots, left behind on Earth in 2105 to clear up humanity’s waste by baling it and stacking it into these colossal structures.
Inspired by this image, I thought what would 8 million tonnes of plastic look like in tower form. What if we baled all that plastic and piled it up so that it resembled a skyscraper? Now we need a real-world skyscraper to model these plastic towers on. Let’s go with the obvious choice, the Empire State Building. It's iconic for a reason, after all. So, how many Empire State Buildings could we recreate out of 8 million tonnes of plastic?
CALCULATIONS
First off, in order to make this simpler and avoid having to think about the weights of different types of plastic, let’s convert all of our 8 million tonnes into half-litre plastic bottles, 50 of which weigh 1 kg. With 50,000 bottles in 1 tonne, that then means our 8 million tonnes consists of 400,000,000,000 plastic bottles, an incredible 51 bottles per person on the planet. Time now to start baling and building.
Unfortunately, this is where things get complicated, since it turns out that the density of plastic bales produced by different balers varies a lot. I won't bore you with the details, but for the sake of this thought experiment we'll go with the Super High Density Baler (60” vertical). This can compact about 18,100 bottles into a bale with a volume of 1.39m3 (dimensions: 0.76m x 1.22m x 1.50m) and a typical weight of 362kg. I can’t say much about whether these imaginary towers would stay standing, but 'super high density' bales sound like a safer bet.
Now that we have the volume and weight of each bale and the number of plastic bottles one would contain, it’s time to think about the volume of the Empire State Building. A quick search told me that its volume is 1,047,723 m3. That volume divided by the volume of one bale (1.39m3) gives me the number of bales that we would need to create one tower with the dimensions of the Empire State Building: 753,758 plastic bales. With each bale weighing 362kg, one tower would therefore weigh 272,860,318kg. In tonnes, that's 272,860. How many towers could we make out of 8 million tonnes then?
8,000,000 ÷ 272,860.318 = 29.3
There we have it. Over 29 Empire State-shaped towers worth of plastic entering our oceans every year.
It’s a disturbing thought, knowing that humanity is polluting the environment to that extent. But we can at least try to put an end to this massive issue by turning off the tap on ocean plastic. That’s why at earthrhize we support Plastic Bank in their goal to clean up ocean-bound plastic while providing a source of income for people suffering from poverty. Remember to sign up to our newsletter, and we will fund the clean-up of 1kg of ocean bound plastic to get you going. Or start subscribing to one of our three plans, if you haven’t already, so that you can join us in whittling down those 8 million tonnes. It’s a long way to go, but we have to start somewhere. You'll also know that you're doing your bit to prevent the Earth looking like it does in WALL-E by the time we get around to 2805… Keep an eye out for further Ever Wondered pieces, in which we will explore further ways of visualising 8 million tonnes of plastic.
