Aerocene
Aerocene is a project to create awareness about the use of fossil fuels. They focus their work on creating hot air balloons made with plastic bags.
From their website:
As an ever growing research and experimental practice, Aerocene is open-source and collaborative. It consists of a dedicated and diverse global community of practitioners who collaborate to promote and enact environmental awareness and atmospheric sensing experiments, imagining new infrastructures of planetary mobility and ethics.
By collaboratively developing, testing and launching aerosolar sculptures, Aerocene seeks to open up the imagination towards an emergent cloudscape, un-tethering a new era of planetary attunement, restoring the thermodynamic balance of the Earth, free from borders, free from fossil fuels.