Hannah Ritchie Profile picture
Deputy Editor @OurWorldinData / Researcher at @UniofOxford / Honorary Fellow at @EdinburghUni @EdCentreCC / Not the End of the World: https://t.co/FoINhggvoR

May 1, 2021, 10 tweets

Where does the plastic in the ocean come from?

A new study published in @ScienceAdvances updates our understanding.

My latest @OurWorldInData article looks at the global picture of plastic pollution: ourworldindata.org/ocean-plastics

Thread of key points 👇

Previous studies suggested a small number of big rivers accounted for most of ocean plastics.

But higher-resolution data suggests many more small rivers play a big role.

To cover 80% of plastic inputs you need to tackle > 1,000 rivers.

1/

Factors that matter a lot for a river's plastic inputs:
– waste management practices
– distance to coast
– cities nearby
– precipitation rates
– slope of terrain

Here are the top 10 rivers 👇
(most are small rivers in the Philippines)

2/

Previous modelling did not have such high-resolution data on topography, terrain, climate etc.

Therefore put more emphasis on the *size* of the river basin. So it assumed: large river basin = lots of plastic inputs.

That's why the latest results are markedly different

3/

The regional distribution of plastic inputs is similar to previous studies.

Most plastic inputs come from rivers in Asia (81%).

4/

But some of the smaller countries in Asia play a larger role.

One-third comes from the Phillippines. It has a lot of small rivers with cities close to the coast.

5/

What people often get wrong about plastic pollution:

They underestimate how important waste management is.

It's not the case that using more plastic use = more pollution.

Most rich countries contribute very little because they manage the waste.

6/

Improving waste management is not a sexy solution. Most people find it boring.

But if you're serious about tackling plastic pollution, this is where to put your focus and investment.

7/

This recent paper is from @LourensWater & colleagues in @ScienceAdvances.

You can check it out here: advances.sciencemag.org/content/7/18/e…

8/

And @TheOceanCleanup has a beautiful high-resolution map with all the rivers that I recommend you check out: theoceancleanup.com/rivers/

/end

Share this Scrolly Tale with your friends.

A Scrolly Tale is a new way to read Twitter threads with a more visually immersive experience.
Discover more beautiful Scrolly Tales like this.

Keep scrolling