As plastic pollution is considered a potential geological marker of the Anthropocene, some living organisms have evolved and adapted into symbiotic relationships with polymers. The wicked problem of pollution and toxic exposure contributes to waste colonialism, which is inherent to the current state of climate and ecological emergency. From plastics to fungi and back again, this project speculates on the possibilities to decolonise plastic waste with the help of a plastic-decomposing fungus. My research prompts toward anthropo-de-centrism and multispecies storytelling as design methods to develop care for plastic waste. The project draws upon the complexity of fungi-plastics-humans relations and is supported by a transdisciplinary collaborative research focused on fungi cultivation. At the core of this practice, I relate the omnipresence of fungi and plastics to queer ecologies, and as such, I develop my design proposal with generative toxicity as theoretical and creative framework.  To materialise this, I propose a workshop bridging between local communities of designers and self-taught mycologists, in order to change the general opinion on plastic waste by focusing on hosting and care as forms of slow activism. The longer-term aim would be a systemic rebalancing of our permanently polluted world. Queer ecologies could therefore contribute to refine what sustainability means for design today by facilitating multispecies care and decolonising gestures.

Plastics pollution is a global planetary threat to both humans and the environment, leading to injustice throughout its lifecycle and disproportionately affecting the most vulnerable. The United Nations Environmental Assembly adopted Resolution 5/14 to create a legally binding instrument to end plastics pollution, known colloquially as the Plastics Treaty. The treaty is currently under negotiation, and the implicit understandings of justice that will be incorporated will significantly impact the outcome of the treaty. This thesis employs critical discourse analysis and key stakeholder interviews to examine the various justice narratives and framings of actors in the treaty through an environmental justice lens. Additionally, the role of power in shaping these narratives is examined from a critical and decolonial perspective. My research demonstrates the value of a critical approach in addressing power dynamics and normative concepts such as justice in social-ecological and sustainability research. This study identifies three distinct discourses, each offering different problematizations of plastics and justice framings. The analysis reveals competing definitions of just transition, a disconnect between the recognition of Indigenous Knowledge and the rights of Indigenous People, and underdeveloped gender and intersectional considerations. Furthermore, this thesis highlights the enduring influence of colonial dynamics on plastics pollution, potentially reinforcing waste colonial relations in the Plastics Treaty. Finally, this thesis contends that problematizing plastics as a human rights issue offers a valuable approach to address these shortcomings, thereby enhancing the treaty's potential for promoting justice by ensuring that the voices of those most affected are heard.