Hannah Ritchie Profile picture
May 1, 2021 10 tweets 4 min read Read on X
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

• • •

Missing some Tweet in this thread? You can try to force a refresh
 

Keep Current with Hannah Ritchie

Hannah Ritchie Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!

PDF

Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @_HannahRitchie

Sep 14, 2023
I've heard several people say that renewables are not driving an "energy transition". It's really just an "energy addition".

This makes it sound like fossil fuels have been business-as-usual, and we've stuck renewables on top.

I think there is a better way of framing this...🧵
In rich countries it really is an "energy transition".

Renewables are replacing fossil fuels in the electricity grid.

And as EVs replace petrol, and heat pumps replace gas (which are in early stages), the broader energy mix will transition too.

1/ Image
In low & middle income countries, energy consumption is growing strongly, so all of the lines are going up.

However, I think "energy addition" is the wrong phrase here. It's more like "fossil energy displacement".

Growth in fossil fuels would be ⬆️⬆️ without renewables.

2/ Image
Read 5 tweets
Jun 4, 2023
Terrible of the @guardian to publish this ill-informed, out-dated article on EVs.

Why does it build so much of its coverage around the climate crisis, then continually publish nonsense articles that undermine real solutions to address it?

theguardian.com/commentisfree/… Image
@guardian Most of the claims in the article are wrong.

You only have to look at the first, on the CO2 emissions of EVs vs. petrol/diesel cars.

Yes, emissions are higher during the production of an EV but this very quickly pays off when you start driving it.

... Image
@guardian Many have covered this in detail:

carbonbrief.org/factcheck-how-…

sustainabilitybynumbers.com/p/ev-fossil-ca…

iea.org/data-and-stati…

Over its life course, the emissions of EVs are lower (how much lower depends on the electricity mix). As the world decarbonises, this will get even better.

...
Read 5 tweets
Mar 29, 2023
What impact have national greenhouse gas emissions had on global warming?

A new paper by @Jones_MattW & team at @gcarbonproject quantifies each country's contribution to global mean surface temperature rise.

I've added this data to @OurWorldInData. Here are some highlights 👇 Image
@Jones_MattW @gcarbonproject @OurWorldInData First, the team calculcates contributions to temperature rise using cumulative emissions of CO2, methane & nitrous oxide since 1850.

They convert this into carbon-dioxide equivalents using the GWP* method.

Includes emissions from fossil sources, agriculture & land use

1/
@Jones_MattW @gcarbonproject @OurWorldInData Here are 5 countries with the largest contributions to global temperature rise.

🇺🇸 USA: 0.28°C
🇨🇳 China: 0.2°C
🇷🇺 Russia: 0.1°C
🇧🇷 Brazil: 0.08°C
🇮🇳 India: 0.08°C

2/ Image
Read 12 tweets
Dec 22, 2022
It's easy to be skeptical that countries are taking little action on climate change.

This isn't true.

Looking at the shift in our trajectory in just a few years tells a different story.

I looked back at the past 6 years of @climateactiontr projections 👇
@climateactiontr 2016.

Policies in place would have taken us to 3.3 to 3.8°C by 2100.

Country pledges to 2.5 to 2.7°C.

1/
@climateactiontr 2017.

National policies: 3.1 to 3.7°C

Country pledges: 2.6 to 3.2°C

2/
Read 11 tweets
Dec 20, 2022
🆕 @f_spooner and I have published a major new redesign of our work on Biodiversity on @OurWorldInData 🐘🦁

A day after the world sealed a new deal on how to limit biodiversity loss & reverse it.

Explore all our data and articles in one place: ourworldindata.org/biodiversity Image
@f_spooner @OurWorldInData This redesign includes a block of Key Insights on the topic 👇

1/ Image
@f_spooner @OurWorldInData A spot where you can find all of our research and writing 👇

2/ Image
Read 4 tweets
Dec 5, 2022
Eating locally is not an effective way to reduce the carbon footprint of your diet.

This is despite a recent paper in @NatureFoodJnl claiming that 'food miles' make up 20% of food emissions.

In my latest Substack post I explain why this is wrong: hannahritchie.substack.com/p/food-miles
@NatureFoodJnl Some of the key points:

The new paper by Li et al. (2021) claimed that 'food miles' were 3.5 to 7.5 times higher than previous studies.

This is only because they redefined 'food miles' (to include things that are definitely not food miles).

1/
@NatureFoodJnl Their own results do not even support 'eating local makes a big difference'

They modelled a scenario where all countries got *all* of their food domestically.

Food emissions were reduced by just 1.7%.

They actually showed the opposite: it was very ineffective...

2/
Read 5 tweets

Did Thread Reader help you today?

Support us! We are indie developers!


This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Don't want to be a Premium member but still want to support us?

Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal

Or Donate anonymously using crypto!

Ethereum

0xfe58350B80634f60Fa6Dc149a72b4DFbc17D341E copy

Bitcoin

3ATGMxNzCUFzxpMCHL5sWSt4DVtS8UqXpi copy

Thank you for your support!

Follow Us!

:(