As spinoffs of the IceCube neutrino observatory, we have developed instruments that descend thousands of meters into boreholes in polar ice and map the pre-history of climate change, volcanic eruptions, and in-situ microbial metabolism with 1-mm depth resolution. We find that ice-bound microbes metabolize at a rate µ exp(-U/kT) via redox reactions of small molecules of atmospheric origin that diffuse through the ice. Microbes from oceans and deserts are deposited episodically onto glacial ice and may serve as proxies for storm frequencies in the last 105 to 106 years. At depths where their local concentration is especially high, their gaseous metabolic products distort the climate record of greenhouse gases. A case can be made that life arose in icy environments on Earth and Mars.