PALEOCLIMATE:
The Sulfur Cycle and Atmospheric Oxygen
Robert A. Berner and Steven T. Petsch
Changes in the ratios of isotopes of sulfur and carbon in seawater and sediment caused by biological processes can reveal much about past climate changes. In their Perspective, Berner and Petsch discuss results reported in the same issue by Paytan et al. on measurements of isotope abundances that overcome difficulties that have plagued previous studies. This new data set should prove useful in understanding atmospheric chemistry in the past, particularly changes in atmospheric oxygen.
The authors are in the Department of Geology and Geophysics, Yale University, New Haven, CT 05620-8109, USA. E-mail: berner{at}hess.geology.yale.edu; steven.petsch{at}yale.edu