Sumner is the author of a widely used anti-harassment statement that she made public so that other universities and institutes could use it as a model. A leader in helping institutions develop anti-harassment plans, Sumner presented to a workshop at the 2016 American Geophysical Union on “Addressing harassment and improving workplace climate.” She was also an invited presenter for Association of Polar Early Career Scientists webinar on sexual harassment during fieldwork. Sumner is presently chair of advisory board for The Feminist Research Institute at the UC, Davis In June 2020 she became the leader of the Anti-Racism Action Committee in her department (Earth and Planetary Science) at UC Davis. Sumner also wrote four letters concerning racism and its effects on the science community between late May and early June 2020