Microbial interactions between climate warming and antimicrobial resistance threaten soil carbon storage and global health.

Anthropogenic activities are impacting the environment in ways that may intersect and have compounding effects. In soil, the spread of antibiotics and resistant microbes, and thereby antimicrobial resistance (AMR), can accelerate because of climate change and anthropogenic activities. Here we propose that the dual production and release of antimicrobial compounds to the environment, and the increase in global temperatures as a consequence of climate change, will have synergistic effects leading to both enhanced climate change and disease risk. We predict that an increase in AMR will reduce microbial carbon use efficiency (CUE) because interactions amongst microbes will lead to the allocation of available resources towards AMR and metabolism instead of growth. This reduction in CUE may lead to increased greenhouse gas release; however, the extent to which AMR can affect the stability of soil carbon by altering microbial CUE remains unknown. This concern is especially pertinent in the Arctic, which is warming faster than anywhere else on Earth and contains substantial soil carbon reservoirs.