Neil Foley, University of California Santa Cruz, Department of Earth and Planetary Sciences, Santa Cruz, CA, United States, Slawek M Tulaczyk, Univ California Santa Cruz, Earth and Planetary Sciences, Santa Cruz, CA, United States, Esben Auken, University of Aarhus, Aarhus, Denmark, Denys Grombacher, Aarhus University, Aarhus C, Denmark, Nikolaj Foged, Gaborone, Botswana, Jill Mikucki, University of Tennessee, Department of Microbiology, Knoxville, TN, United States, Peter T Doran, Louisiana State University, Geology and Geophysics, Baton Rouge, United States, Krista Myers, Louisiana State University, Baton Rouge, United States, Hilary A Dugan, University of Wisconsin, Madison, WI, United States and Ross A Virginia, Dartmouth College, Environmental Studies Program, Hanover, NH, United States