His research, over the last twenty five years, has focused on complexity and systems theory and their application to the development of an ecosystem approach as a way of understanding and managing our role in the biosphere. His research activities span the full spectrum from the theoretical and epistemological basis for an ecosystem approach, to the formulation of ecosystem based environmental policy, the development of ecosystem monitoring programs, to on the ground ecosystem planning both in the context of urban, industrial, and natural ecosystems and the greening of institutions. With D. Waltner-Toews, he is preparing "The Ecosystem Approach: Complexity, Uncertainty, and Managing for Sustainability" for the Columbia University press series: Complexity in Ecological Systems.
Dr. Kay was founding Chair of the University of Waterloo's Greening the Campus Committee (1990-96) This committee is responsible for overseeing the transition to a sustainable campus. This undertaking, the oldest in Canada, has received four environmental awards, and was the subject of an article in the Times of London Sunday Supplement and reported on in University Affairs.
Dr. Kay was a founding member of the City of Kitchener's Environment Committee. This committee has developed and implemented a Strategic Plan for the Environment for Kitchener. With his students, he has worked closely with the City of Kitchener on the development of an ecosystem based master plan for the Huron Natural Area. He was part of the committee which developed the award winning (Canadian Institute of Planners) bicycle master plan for the city. He currently sits on the Kitchener committee for the Transistion to a hydrogen economy, a corporate goal of the City of Kitchener.
Dr. Kay served on the Long Term Ecosystem Research and Monitoring Panel of the Royal Society of Canada and was a member of the Royal Swedish Academy of Sciences, Beijer Institute, Working Group on Complex Ecological Economic Systems Modeling. He was a founding member of the Board of Directors of the International Society for Ecosystem Health. He is vice-president of the Network for Ecosystem Sustainability and Health (NESH). He is the chair of the ecosystem special integration group of the International Society for Systems Science. He currently sits on the United States National Science Foundation Advisory Committee on Environmental Research and Education. He was the Chair of the NSF AC-ERE task group: strategic planning for environmental research and education.
He was the scientific advisor for the Centro Internacional de Agricultura Tropical Project "Development and Applications of an Integrated Conceptual Framework for Tropical Agroecosystems Based on Complex Systems Thinking. With D. Waltner-Toews, he advised the International Development Research Council of Canada on developing an ecosystem approach to health. He is currently on the science review panel for: Local Unit Criteria and Indicator Development Project (for sustainable ecosystem management) of the USDA Forestry Service Inventory and Monitoring Institute, and the COllaborative MErcury Research Network - COMERN.
He prepared for the Canadian Environmental Advisory Council, a commissioned background paper The Concept of "Ecological Integrity", Alternative Theories of Ecology, and Implications for Decision-Support Indicators. This paper was one of the motivators for the Tri-Council Eco-Research Fund. He advised Environment Canada and the North American Commission for Environmental Cooperation on the theoretical basis for State of the Environment Reporting, writing for them: The Ecosystem Approach, Ecosystems as Complex Systems and State of the Environment Reporting. With C. Pupp and H. Regier, he develop a framework which was used as the basis of the St-Lawrence/Great Lakes chapter of the current Canadian State of the Environment report. With M. Boyle and B. Pond, he developed a framework for State of the Landscape Reporting for the Ontario Ministry of Natural Resources. This framework is being used as the basis for the provincial monitoring program that is required under the new Ontario Planning act. He wrote the chapter on monitoring for the Encyclopedia of Global Environmental Change.He has worked extensively on the development of a framework and measures for evaluating ecosystem integrity. He co-authored the book: Ecological Integrity and the Management of Ecosystems. His thinking on the ecosystem approach is summarized in the article: An Ecosystem Approach For Sustainability: Addressing The Challenge Of Complexity in the journal Futures (September, 1999) and in the review article "Perspective changes everything: managing ecosystems from the inside out", in the journal Frontiers in Ecology and the Environment (Vol.1, 2003)
Dr. Kay, with E. Schneider, has published a number of papers on the role of the second law of thermodynamics in understanding complexity and ecosystem dynamics. This research was the subject of the cover story in New Scientist, 5 October, 2002. His most recent publication in this regard is: Ecosystems as Self-organizing Holarchic Open Systems: Narratives and the Second Law of Thermodynamics in theHandbook of Ecosystem Theories and Management. One of his papers with Scheider ("Life as...") was recently identified as one of the 12 most important papers in ecology 1970-1999 to be published in Charles Curtin and TFH Allen, Ecology at the end of the millenium, Chicago University Press. It has also been published as part of the Oxford University Press Readings in Ecology.
His WWW site has been cited in The Infography as "one of the most excellent sources of information" about the subject of "Thermodynamics -- Ecological".