Overview
Open Litter Map is a free app and website that lets anyone photograph litter and add it to a public world map of pollution. You take a photo of a piece of trash on the ground, tag what it is (a plastic bottle, a cigarette butt, a chocolate wrapper) and where it was found, and the dot lands on a global map that researchers, councils, and schools use to track plastic pollution.
The project was started in Ireland in 2017 by geographer Seán Lynch and is recognised by the Digital Public Goods Alliance, a United Nations-backed catalogue of open tools that support the Sustainable Development Goals1. Verified contributors can earn Littercoin, a community reward token that runs on the Cardano network. Open Litter Map is also part of Cardano4Climate, a working group of environmental projects in the Cardano ecosystem.
Key Features
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A global map of real-world litter. Every verified photo lands on a public, browsable map, and a live feed on the homepage shows fresh uploads as they come in from around the world2.
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Tag the brand, not just the trash. Contributors record the object, the material, and the brand printed on the packaging, so the dataset can show which companies' products turn up most often in the environment3.
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Reward for open data. Verified contributors earn Littercoin, a community reward token on the Cardano network4. Littercoin is meant for community use, not exchange trading, so you do not need to buy or sell anything to take part.
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Listed as a Digital Public Good. Open Litter Map appears in the official Digital Public Goods Alliance registry, the United Nations-backed list of open-source tools that advance the Sustainable Development Goals1.
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Open code, peer-reviewed origins. The full platform is open source on GitHub under a GPL-3.0 licence, and the original concept was published as a peer-reviewed paper in Open Geospatial Data, Software and Standards3. The dataset has since been cited in dozens of academic studies5.
What to Expect
Open the homepage and you see a live feed of fresh uploads from around the world, plus a global map you can zoom into. Drill down to a country, a city, or a street to see what has been logged near you. There is also a contributor leaderboard, country-by-country pages, and a public reading list of studies that have used the data.
To contribute, you sign up for a free account with just an email, install the mobile app, and start photographing litter. First-time uploads are reviewed by a small admin team before they go public, and regular contributors get verified faster through community review2. Tagging is point-and-pick from a library of object, material, and brand options, so most people post their first photo within a few minutes of signing up. The app works in several languages, on phones, tablets, and laptops.
If you mainly want to use the data, downloads and the academic reference list are on the site itself. If you want to contribute code or follow development, the work happens openly on GitHub and Project Catalyst.
