Introduction
Blockchain is a very powerful tool that can be implemented in many different projects especially in the city scale. We decided to use blockchain technology to fight with air pollution problem, because current systems are either concentrated on rising people’s awareness, compliance the required standards or providing necessary tools. We consider blockchain as the missing element to change people’s behavior by rewarding decisions we make in everyday life that can contribute to the prevention of air pollution.

What makes blockchain the right tool to do that is that it provides greater transparency, enhanced security, improved traceability and increased efficiency and speed of transactions.

General concept
The main concept of our project is that user registered on the blockchain, makes everyday decisions that can either contribute to air pollution or to reduction of air pollution. Each of these actions is registered on the blockchain and people who make pro-environmental decisions are rewarded with an adequate number of tokens which can be spend by receiving certain benefits instead.

Earning tokens
Every day we have the opportunity to make decisions that can contribute to the prevention of air pollution, whether by choosing a mean of transportation or by doing everyday shopping. Any action that is considered beneficial for the environment will be rewarded with the tokens received on the mobile application.

Actions are rewarded in proportion to the contribution they have in the prevention of air pollution. The only limitation we had was the ability to track the action – not every decision that matters is possible to register.

Spending tokens
Tokens obtained in this way can be spend in many ways, for example counting down from tax settlement, or having discount for education payment or public transportation.

 Conclusion
This project is an example how blockchain can be used in combating air pollution problem in the cities and it needs further development. The idea of the project was also to pay attention that everyday decisions and habits might be the source of air pollution that can easily be change by enhancing people to make right choices.

Blockchain to fight air pollution is a project of IaaC, Institute for Advanced Architecture of Catalonia developed at Master in City and Technology in 2018/2019 by:
Students: Wei Wei and Jaroslaw Kowalski
Faculty: Luïsa Marsal