1. Godwin Laboratory for Palaeoclimate Research, Earth Sciences DepartmentUniversity of Cambridge Cambridge UK
2. Institute of Geological Sciences and Oeschger Center for Climate Change ResearchUniversity of Bern Bern Switzerland
3. Now at Lamont‐Doherty‐Earth‐ObservatoryColumbia University Palisades NY USA
4. Scripps Institute of OceanographyUniversity of California, San Diego La Jolla CA USA