Immortal Worlds? is a collaborative project between artist Jac Scott and myself, with our initial investigations being funded by an A-N New Collaboration Bursary. The focus of the project is on mapping the unseen, but vitally important world of bacteria and, particularly how climate change will impact on these organisms, which underpin all of the Earth’s many diverse and living ecosystems. We aim to create innovative and collaborative studies that will not only experimentally and critically engage art and science, but will also spark debate about our rapidly changing world. Our initial explorations have been to replicate natural microbial ecosystems from important environments like salt marshes, wilderness areas, and various water courses, and then to mimic the predicted effects of global warming, like increased temperature, in the laboratory, and finally to observe the outcome. These images are from microbial ecosystems that have been established from a salt marsh in Blakeney, Norfolk. One set of ecosystems has been incubated at temperatures that we might encounter today, and the others at a higher temperature that might be the outcome of global warming. The differences in the health and diversity of the ecologies is both striking and frightening, the low temperature ones flourishing and exhibiting great diversity, with the higher temperature systems being dominated by a form of grey monotonous life and appearing far less balanced.