James Callan Gray Wessel Walker, professor emeritus of atmospheric, oceanic and space sciences, died peacefully at home Dec. 10, 2022, at age 83 after a long illness.
Jim was born Jan. 31, 1939, in Johannesburg, South Africa. As a child he attended Cordwalles Preparatory School, where one teacher wrote that “his is one of the best mathematical brains I have encountered here in 29 years.” He graduated from Michaelhouse and was awarded a full scholarship to Yale University from the Robin Line, a shipping company.
He received his Bachelor of Science degree from Yale in 1960 and his Ph.D. from Columbia University in 1964. Following postdoctoral appointments at Queen’s University in Belfast and at NASA’s Goddard Space Flight Center, Jim first served on the faculty of Yale University and then directed the Ionospheric Section at the Arecibo Observatory in Puerto Rico.
He came to the University of Michigan in 1980 as a professor of atmospheric, oceanic and space sciences, and was also appointed professor of geological sciences. He was named an Arthur F. Thurnau Professor in 1993 for outstanding innovations in undergraduate education.
Jim is best known for his studies on the origin and evolution of the Earth’s atmosphere and the chemical composition of the oceans. He made seminal contributions on the conditions necessary for the origin of life. His book, “Evolution of the Atmosphere,” has been widely used.
His later work focused on the interactions of carbon dioxide and the changes in surface temperature of the planet. He was an active researcher in both natural and anthropogenic climate change. Jim was a strong supporter of environmental studies and served as director of the LSA Environmental Studies Program from 1991-98.
Jim was devoted to his family, friends and to the art of living well. With the family, he pursued bicycling, sailing, hiking, gardening and Scottish country dancing. He and his wife, Donna, supported the arts and enjoyed attending concerts and operas in Ann Arbor and Detroit.
Jim was very active in the church choir and community theatre, and as a regular volunteer at The Breakfast at St. Andrew’s. His baking won many blue ribbons and champion prizes at the Michigan State Fair and Ionia Free Fair. Most of all he valued time with family at their second home in the woods of west Michigan.
Jim was a lifelong activist in the causes of non-violence, racial justice and peace. As a graduate student, he worked to register Black and Hispanic voters in New York City. He also participated in major anti-Vietnam War demonstrations, including the group that “levitated” the Pentagon. He protested the draft with Abbie Hoffman and was arrested with Allen Ginsburg (and a few hundred others) for civil disobedience.
His activism continued with regular participation in marches, including protests against the invasion of Iraq, protests with Moms Demand Action, the 2017 Women’s March, and ongoing support for the Black Lives Matter movement. He was a longtime election inspector and served as a precinct chair.
Jim will be remembered for his unfailing humor and good cheer, great kindness and intellectual seriousness. His cheerfulness and patience endeared him to those who knew him even slightly. His generous nature will be truly missed by family and friends.
Jim is survived by his wife of 40 years, Donna, and his children: John Walker (Natalia Bobrova), Kate Gaertner (Paul), Mary Wessel Walker (Zlatko Pavloski) and Margaret Wessel Walker, as well as grandchildren Alexander, Annabelle, Melody, Mira and James.
— Submitted by Donna Wessel Walker
