Abstract Plastics in the marine environment have become a major concern because of their persistence at sea, and adverse consequences to marine life and potentially human health. Implementing mitigation strategies requires an understanding and quantification of marine plastic sources, taking spatial and temporal variability into account. Here we present a global model of plastic inputs from rivers into oceans based on waste management, population density and hydrological information. Our model is calibrated against measurements available in the literature. We estimate that between 1.15 and 2.41 million tonnes of plastic waste currently enters the ocean every year from rivers, with over 74% of emissions occurring between May and October. The top 20 polluting rivers, mostly located in Asia, account for 67% of the global total. The findings of this study provide baseline data for ocean plastic mass balance exercises, and assist in prioritizing future plastic debris monitoring and mitigation strategies.
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The only study on this subject I'm aware of is the one funded by The Ocean Cleanup Foundation [1], which puts 86% of annually released plastic in Asian rivers, with the main contributor being the Chinese Yantze river, followed by the Ganges. This compared to a mere 0.28% and 0.96% for Europe and North America respectively.
They've also released an interactive map [2], although if you're just interested in the numbers I'd recommend reading the paper.
[1]: https://www.nature.com/articles/ncomms15611.pdf
[2]: https://www.theoceancleanup.com/sources/
"We" in the case of plastic:
Lebreton, L., van der Zwet, J., Damsteeg, JW. et al. River plastic emissions to the world’s oceans. Nat Commun 8, 15611 (2017). https://doi.org/10.1038/ncomms15611
Carbon emission is only one of all our ecological concerns. I don't know why people only think about carbon.
You can look for example at River plastic emissions to the world’s oceans [1].
[1] https://www.nature.com/articles/ncomms15611
No. That's incorrect. This study published in Nature (2017) by the Ocean Cleanup researcher contradicts your statement entirely:
https://doi.org/10.1038/ncomms15611
> Our model is calibrated against measurements available in the literature. We estimate that between 1.15 and 2.41 million tonnes of plastic waste currently enters the ocean every year from rivers, with over 74% of emissions occurring between May and October. The top 20 polluting rivers, mostly located in Asia, account for 67% of the global total. The findings of this study provide baseline data for ocean plastic mass balance exercises, and assist in prioritizing future plastic debris monitoring and mitigation…
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strategies.
The likelihood of your trash ending up in the ocean depends entirely on where you live and how your trash gets processed.
The only part of your statement that's somewhat correct is that rivers in developed countries carry less plastics to the oceans compared to developing countries. But "very little" is creating a false impression of the problem.
Processing disposable plastic waste is a problem that can be avoided by... not using disposable plastics at all. This is first and foremost a moral choice: whether or not we want to put the health of the ecosystem of which we are part above our own personal short-term convenience.
Thailand banned the use of disposable plastic bags this month:
https://phys.org/news/2020-01-thai-retailers-single-use-plas...
You'd think that the Thai would oppose the ban. That's not what's happening if you gauge the sentiment on social media:
https://www.boredpanda.com/unusual-ways-people-dealing-plast...
I don't believe this. -- About two years ago there was a study which said that 88 to 95 percent of the total global load of plastics in the oceans [edit: wrong see below] would come from 10 rivers:
- https://phys.org/news/2017-10-plastic-rivers-stem-plastics-o...
- https://www.nature.com/articles/ncomms15611 and link to table https://www.nature.com/articles/ncomms15611/tables/1
Still, of course, fishermen shouldn't throw their plastic bottles over board and better care to their fishing nets.
I believe the paper that lead to all of those articles blaming the plastics in the ocean on Asian rivers was one that was specifically looking looking at plastics carried by major river systems [1]. This was to complement a previous study on plastics from coastal strips [2]. The large Asian river systems have catchment areas that hold billions of people between them and would carry a substantial proportion of the worlds riverine pollution even if all other things were equal. The microplastics in the environment in the first world come from first world activities, including littering and driving (and hence producing car tyre fragments).
Low and middle income countries need…
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better public services - including waste and waste water management - and enforcement of environmental laws. High income countries need less waste and enforcement of environmental laws.
[1] https://www.nature.com/articles/ncomms15611.pdf
[2] https://science.sciencemag.org/content/347/6223/768.full https://jambeck.engr.uga.edu/landplasticinput "There is one high income country on the list, the United States, and while our waste management systems are well-designed and very effective, and the only mismanaged waste is from litter, we have a large coastal population and a large waste generation rate."
Rivers are of particular interest because they represent the primary mechanism by which inland plastic finds it's way into the ocean. Coastal releases of plastic only happen in coastal regions. Granted, most of the world's population lives reasonably close to a coast, but even in those regions the plastic waste is often carried to the ocean by water through smaller waterways, such as rain water carrying plastic litter down storm drains. (Or the waste is left directly on the beach and the next high tide picks it up.)
This article goes into the correlation between plastic waste in Asian rivers and Monsoon season: https://www.nature.com/articles/ncomms15611
That correlation…
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suggests that a large portion of plastic in Asian rivers is being carried into those rivers by rain water, a similar mechanism to how plastic waste is emitted from coastal regions.
Of course there are other mechanisms in play too, such as municipalities deliberately, perhaps illegally, dumping their waste into rivers or off a coast. But a ton of it is coming from ground litter either left directly on the beach or carried to the ocean one way or another by water. Regions with the heaviest rain and the most ground liter are the biggest contributors, as you would logically expect.
The western world is responsible for 1,25 % of all ocean plastic pollution. Europe is only 0,28 %![0] There is no need to ban single-use plastics in the West. It's just virtue signaling and the so-called 'solutions' lower our comfort, will cause a rise in food poisoning deaths and are worse for the environment.[1]
When you mention this, people reply we should set an example and other countries will follow. The idea that Western countries should set an example to teach those 'dumb countries that can't think for themselves' how to do things seems very arrogant. And there are zero guarantees it will work. If it was as easy as setting an example, every country on earth would…
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be a blossoming democracy by now...
[0]
https://www.nature.com/articles/ncomms15611#f1
[1]
https://www2.mst.dk/Udgiv/publications/2018/02/978-87-93614-...
Edit:
An actual solution would be if the EU invested in waste management solutions in the developing world.
People mention micro-plastics as a bad thing but we don't know that yet. So far the level of evidence proving micro-plastics as harmful is on par with the evidence linking cancer to cellphones.
There are a lot of comments in this thread shitting on this project for not doing their cleanup at the rivers, but failing to realize that that reason we've identified those rivers as the source of ocean plastic is because of The Ocean Cleanup project's paper in Nature Communications:
https://www.nature.com/articles/ncomms15611
The article slips in a link to a fact which i think is not well known, but rather imporant - the punchline is in the URL slug:
http://www.dw.com/en/almost-all-plastic-in-the-ocean-comes-f...
> It turns out that about 90 percent of all the plastic that reaches the world's oceans gets flushed through just 10 rivers: The Yangtze, the Indus, Yellow River, Hai River, the Nile, the Ganges, Pearl River, Amur River, the Niger, and the Mekong (in that order).
> These rivers have a few key things in common. All of them run through areas where a lot of people live — hundreds of millions of people in some cases. But what's more important is that these areas don't have adequate waste…
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collection or recycling infrastructure. There is also little public awareness that plastic trash is a problem at all, so a lot of garbage, gets thrown into the river and conveniently disappears downstream.
The biggest thing we can do to fix the ocean plastic pollution problem isn't visionary technology like Slat's cleanup machine (don't get me wrong - we should cheer that project on!), or virtuous self-flagellation like using reusable drinking straws, it's good old fashioned hard work: hire more bin men, and put up more information posters.
EDIT: Here's another paper, applying related methods and coming to a broadly similar, although fatter-tailed, conclusion - "The top 20 polluting rivers, mostly located in Asia, account for 67% of the global total":
https://www.nature.com/articles/ncomms15611
One of the authors on that paper is Boyan Slat!
SECOND EDIT: The latter paper includes a couple of sentences i struggle to reconcile:
"We estimate that between 1.15 and 2.41 million tonnes of plastic waste currently enters the ocean every year from rivers" ... "It has been estimated that between 4.8 and 12.7 million tonnes of plastic enters the ocean every year from coastal populations worldwide".
I'm not sure if they're quoting the 4.8 - 12.7 figure to endorse it (coastal populations significantly outweigh rivers) or criticise it (ie it's rivers, not coastal populations).