We live in a world governed by multiple, interlinked, biophysical processes. The planetary boundaries framework defines a safe operating space for humanity based on these processes, which regulate the stability of the Earth as a system1,2. According to the Stockholm Resilience Centre, six of nine planetary boundaries that are crucial for human survival were breached in 2024. Breached boundaries range from biogeochemical flows to climate change and biosphere integrity. Remarkably, the impacts of planetary stress on the most abundant form of life – microbes – are mostly absent from the 2023 assessment3. Microbes not only represent the vast majority of phylogenetic diversity on earth, but also created and maintain many of the planetary systems humanity relies on4. What can explain this lack of attention? In what follows, we highlight that the neglect of microbial health within our environment is not unique to current planetary boundary reports but extends to the most visible microbial crisis of our time – antimicrobial resistance (AMR). We argue that reconceiving AMR not only as a clinical or productivity challenge but as a sign of ecosystem stress enables us to move from merely maintaining drug efficacy to stewarding the wider microbial commons and protecting planetary systems from being breached.

AMR is a natural microbial response to the selective pressure of natural and synthetic molecules and predates the industrial era by millennia5. Over the past 100 years, humans have accelerated selective pressure by releasing selective compounds, including recognised antimicrobials, throughout the biosphere. The result has been a surge in AMR6,7. Unsurprisingly, humans have primarily made sense of this surge not from a microbial but from an anthropocentric perspective. Best captured by the term ‘drug fastness’, which was first used to describe AMR around 1910, the dominant clinical gaze reduced microbes’ resistance phenotype to a binary of treatment success or failure8. Even after the rise of bacterial genetics from the 1940s onwards, AMR’s wider evolutionary and ecological significance remained overshadowed by medical metrics such as the ‘breakpoint’, which adjudicated whether AMR was worth taking seriously or not in a clinical setting9,10,11. Priorities were also reflected in microbiological record-keeping, which rarely recorded long-term AMR creep in the form of minimum inhibitory concentrations (MICs) and usually neglected accelerating change in environmental microbes and microbiota.

Anthropocentric reduction of AMR to a binary of therapy success or failure prompted a utilitarian approach to antimicrobial stewardship that sought to stabilise sensitivity in relation to individual bug-drug combinations but rarely considered ecosystem impacts of drug usage10,12. This neglect of wider microbiota impacts of expanding antimicrobial infrastructures in food and health systems continued despite pioneering 1970s research indicating the proliferation of resistance-bearing plasmids in soil and water samples13,14,15,16. Indeed, it has only been over the last two decades that awareness of the broader ecosystem impacts of antimicrobial exposures has significantly risen in the microbiological and biomedical communities. Advances in genomics have enabled researchers to not only model the global dispersion of AMR genes, but also to track the accelerating historical abundance of these genes using archived soil samples and lake sediments6,17,18,19,20. From the perspective of many microbes, it seems that AMR is fast becoming a precondition for survival on an increasingly polluted and selective planet. Meanwhile, emergent microbiome and metagenomic research is indicating that increasing AMR is associated with microbiome shifts in humans21,22 and the environment23,24 and modulation of these microbiomes, at least within humans, is being explored as a valid therapeutic approach to preventing AMR proliferation25,26.

Despite many invocations of ‘One Health’, defined here according to the WHO as “an integrated, unifying approach to balance and optimise the health of people, animals and the environment”27, the ecological or environmental microbial perspective remains mostly absent from public or policy fora28. As evidenced by the 2024 high-level UN General Assembly (UNGA) meeting on AMR, AMR continues to be primarily conceptualised as a therapeutic or productivity challenge that can be ‘solved’ by an intensification of decades-old stewardship and innovation programs29. By contrast, the planetary environment is more briefly dealt with, specifically from a pharmaceutical production and pollution lens, advocating increased AMR surveillance within health systems with little consideration of the state of our microbial commons.

It is undeniable that maintaining access to effective antimicrobial treatments is essential. However, it is equally clear that continuing to adhere to a self-limiting clinical conceptualisation of AMR will do little to address the environmental drivers of planetary AMR emergence and persistence. Neglecting environmental burdens also glosses over crucial questions about the equity of stewardship frameworks in a world in which both the distribution of disease burdens and of selective exposures is inherently unjust30,31,32. It is becoming clear that stewardship protocols developed in high-income countries may not work in resource-limited settings with far higher loads of selective pollutants in their soil, water, and air as a consequence of decades of Northern outsourcing6.

Reframing AMR not as a problem of human control over microbes but as a sign of stress within our ecosystems opens the door for meaningful integration of AMR governance with debates about planetary boundaries and the health of our microbial environments amidst accelerating planetary stress. It also empowers us to develop longer-term concepts of stewardship that go beyond protecting the efficacy of individual molecules to stewarding the microbiota our lives and livelihoods depend on. This includes firmly anchoring microbial stewardship in international law – including the newly recognised human right to a healthy, clean and sustainable environment – and reconceptualising planetary boundary frameworks to encompass AMR and microbial health33. And finally, it breaks with a tradition that allocates equal responsibilities for pharmaceutical stewardship to communities suffering from high historical pollution loads and those who disproportionately benefited from the industry, resulting in that pollution. Over 115 years after bacteriologists first started analysing drug fastness, the state of our microbial commons should no longer be a side issue but the central theme within AMR conversations.