James Callan Gray Wessel Walker

James Callan Gray Wessel Walker died peacefully at home on December 10, 2022, at the end of a long illness.

Jim was born on January 31, 1939 in Johannesburg, South Africa, the only son of Joyce (Gray) Walker and John “Scotty” Walker. 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.” Jim graduated from Michaelhouse, a boarding school in KwaZulu-Natal, South Africa and was awarded a full scholarship to Yale University from the Robin Line, a shipping company, which included round trip passage between South Africa and New York. He received his B.S. 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 served on the faculty of Yale University and headed the Ionospheric Section at the Arecibo Observatory in Puerto Rico. He came to the University of Michigan in 1980 as professor of atmospheric, oceanic, and space sciences and was also appointed professor of geological sciences. He was honored with an Arthur F. Thurnau Professorship in 1993 for outstanding, innovative contributions to undergraduate education.

Jim began his career by making fundamental contributions to understanding optical emissions and the energy balance of the Aurora Borealis. He then undertook ionospheric research through the use of backscattering radar. He is perhaps 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 by both specialists in the field and atmospheric scientists alike. 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 human-caused climate change. Jim was a strong supporter of environmental studies and served as director of environmental studies from 1991-98. Through his teaching both inside and outside the classroom, Jim made countless people aware of the relevance and importance of our interactions with, and influence upon, the environment. In his later years, Jim had the dubious satisfaction of seeing many of the predictions of climate change researchers like himself come to pass.

Upon his retirement in 2000, Jim devoted himself wholeheartedly to his family and friends, and to the art of living well. He spent time bicycling, sailing, hiking, and gardening with his family. He enjoyed Scottish country dancing and using a spinning wheel to make yarn. He took up singing and joined the choir at church. He also became very active in theater, performing with the University of Michigan Gilbert and Sullivan Society, Comic Opera Guild, Arbor Opera, and the St. Andrew’s Players, where he is best remembered for his roles as Captain Hook in Peter Pan and Lazar Wolf in Fiddler on the Roof (twice). He became a regular volunteer at The Breakfast at St. Andrew’s. He also continued his ongoing passion for cooking and baking, specializing in meals made with local ingredients. He figured out systems that allowed him to keep the family stocked with homemade bread, cookies, and more. He brought his scientific mind to perfecting his recipes, and took many blue ribbons and champion prizes at the Michigan State Fair and Ionia Free Fair, where the open judging allowed him to learn techniques from experts in home baking. He was noteworthy as one of the only men in a room full of competitive baking women, studiously taking notes on how to make the best biscuits, bread, and pies. He and Donna enjoyed supporting the arts and attending concerts at the University Musical Society, Detroit Symphony, the Academy of Early Music in Ann Arbor, and performances by Michigan Opera Theater. Most of all he valued time with family at their second home in west Michigan, enjoying the peace of the woods.

A lifelong activist, Jim was devoted to the causes of non-violence, racial justice, and peace. As a graduate student, he worked with the Riverside Democrats to register Black and Hispanic voters in New York City. He also participated in major anti-Vietnam War demonstrations and was part of a 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 long-time election inspector and served as precinct chair.

Jim will be remembered for his unfailing humor and good cheer, infinite kindness, and intellectual seriousness. A life-long learner, he always respected and sought the expertise of others, never missing an opportunity to add to his store of knowledge from sources ranging from farmers to professors. His cheerfulness and patience made him popular and beloved by those who knew him even slightly. His loving nature will be truly missed by family and friends.

Jim is survived by his wife of 40 years, Donna, whom he met at St. Andrew’s Episcopal Church in Ann Arbor, 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, and Mira. Jim is also survived by his lifelong best friend, Dennis Clackworthy, and many dear friends and extended family members around the world.

Memorial gifts in Jim’s honor may be made to The Breakfast at St. Andrew’s, St. Andrew’s Episcopal Church, or the climate action group of your choice.