Paul Butler is currently Coordinator of the EU consortium project ARAMACC ("Annually Resolved Archives of MArine Climate Change") and Research Lecturer in Sclerochronology and Scleroclimatology, funded through the Climate Change Consortium for Wales (C3W).
After a 25-year career as an IT consultant in London, Paul Butler started an undergraduate degree in Ocean Science at SOS in 2001 and was awarded a First Class Honours degree in 2004. He began his PhD immediately afterwards, working on the use of the shell of the bivalve Arctica islandica as an environmental proxy for Irish Sea waters and building what was then the longest (at 487 years) absolutely-dated chronology based on molluscan growth increments.
He was awarded his doctorate in 2009, and went on to work on MILLENNIUM, an EU FP6 collaborative investigation of European climate of the past millennium. The SOS contribution was to develop the use of A. islandica as a proxy archive for the Polar frontal region on the North Icelandic Shelf; the group were able eventually to build a 1,357 year archive that included one remarkable specimen with a lifetime of 507 years (Butler et al 2012).
The main focus of Paul Butler's research is the construction of precisely-dated high-resolution proxy archives for the marine environment. Some species of bivalve mollusc deposit distinct annual increments in their shells, so if the date of death of the animal is known, the whole of the shell can be dated by counting increments. Most of his research to date has concentrated on the very long-lived bivalve Arctica islandica. A. islandica has been found to live longer than five hundred years (Butler et al 2012), making it the longest lived non-colonial animal whose lifespan can be authenticated. The fact that they grow synchronously within populations allows subfossil shells to be dated by comparing their increment width patterns with the patterns in overlapping shells whose dates are already known, so that the length of precisley-dated archives can be extended back in time. The statistical methods used to build the archives, to compare them with environmental variables and to reconstruct the variables are similar to those used by tree-ring researchers.
Using these techniques, he was able to construct what was then the longest (at 487 years) shell-based archive using A. islandica from waters around the Isle of Man (Butler et al 2009, 2010). Subsequently (in collaboration with Dr Alan Wanamaker, a colleague on the MILLENNIUM project) a 1,357-year A. islandica archive has been built with shells from the North Icelandic Shelf. A recent paper (Wanamaker et al 2012), published in Nature Communications, builds on the Iceland archive, using radiocarbon analysis to show changes in the strength of the Atlantic Meridional Overturning Circulation during the past millennium. Stable isotope analyses of the Iceland shells is now being carried out, with the goal of reconstructing a 1,000-year record of seawater temperatures.