Microorganisms are the most ancient, most abundant and most successful form of life on Earth. For more than 3 billion years, the microbial metabolism, coupled with geophysical processes, orchestrated major biogeochemical cycles on Earth. Microbial life even endured periods of global glaciations such as those 600 and 700 million years ago when Earth was a snowball. In the aftermath of each snowball Earth and after each ice age, streams fed by glacial melt waters dominated the continental landscapes. Today, climate change is causing the icy streams and their glaciers to disappear at rapid pace. But it is not just water that is lost — we may also lose a unique microbiome that possibly carries ancient biosignatures unveiling secrets of the microbial mode of life in these ecosystems millions of years ago. The Vanishing Glaciers project is attempting to uncover some of the characteristics and strategies that microorganisms have developed to become such a successful mode of life in the extreme ecosystems of glacier-fed streams. This will be done by establishing the first census of microbial diversity in glacier-fed streams and combining cutting-edge -omics methods with phylogeny. This research will enable predictions about the impact that climate change may have on the structure and function of the biofilm microbiome and on its orchestration of the biogeochemistry in glacier-fed streams. The Vanishing Glaciers project is being led by Tom J. Battin at Ecole polytechnique fédérale de Lausanne (EPFL), Switzerland.