Walter began his career with Ballard Power Systems, British Gas Investments Canada, and universities more than twenty years ago. He co-founded General Hydrogen Corporation, and Rethink Climate, a company creation platform based in Vancouver. Walter has worked at Canada’s National Research Council (Institute for Fuel Cell Innovation,) and at the Fraunhofer Institute for Solar Energy Systems, in Germany. In British Columbia, he created the Transportation Futures Group, with support from the Pacific Institute for Climate Solutions.

At UBC, Walter has served as director of the Clean Energy Research Centre, as Associate Dean of Research and Industry Partnerships in Applied Science, as a Senior Advisor to the President, as Chair of the Climate Emergency Taskforce, and as a delegate to COP meetings. Currently, he is a Professor of Mechanical Engineering and a Fellow of the Canadian Academy of Engineering. He serves on several boards including those for the New Carbon Economy Consortium, the Climate Change Advisory for Toronto Dominion Insurance, and the Rio Tinto Centre for Future Materials.