He was a masters student at the University of the West Indies, building two homes, and then built concrete boats at a cooperative in Port Antonio, Jamaica in the early 1970s.
He spent two years as government statistician in the British Caribbean colony of Montserrat before moving to Ireland (near Westport) to write and campaign about climate and energy issues and local economic development.
He was a visiting lecturer at the University of Plymouth and contributed the economic content of the Master's course in Theology and the Environment at Dalgan Park, Navan.
He acted as economic adviser to the Global Commons Institute (London) from 1993 to 2005 during which time GCI developed the "contraction and convergence" approach to dealing with greenhouse gas emissions which has now been backed by many countries.
His other major book, Short Circuit (1996) gives dozens of examples of currency, banking, energy and food production systems which communities can use to make themselves less dependent on an increasingly unstable world economy.