The big melt: small cells big consequences

Climate change enhanced melting of the Greenland Ice Sheet has long passed the 1.5˚ C threshold resulting in dramatic melt rates and a large contribution to global sea level rise. Pigmented algae that bloom on snow and ice surfaces as well as dark cryoconite materials exacerbate this melting as they reduce albedo locally by up to 25 %. The algae blooms themselves are fuelled by nutrients, which they derive from melting snow and ice and mineral dust. Such molecular scale mineral – microbe interactions play a fundamental role in the landscape-wide processes that shape our planet now and in a warmer future. Blooms are triggered annually through the tight interplay between geochemical, mineralogica, microbiological and physical processes that we slowly start to unravel. Combining detailed analyses of inorganic and organic components in snow and ice surface measurements with drone and satellite data we can now determine the role that microbes and minerals play in shaping landscape scale processes on Greenland and this helps parameterise global melt and sea level rise model predictions.