Grimalda has actively participated in protest actions, notably as part of Scientist Rebellion, and has campaigned for civil disobedience as a means of promoting climate protection.
Among other things, in October 2022 he and other scientists glued themselves to the floor for forty hours in the pavilion of the Porsche museum in Wolfsburg, this Volkswagen owned location is targeted to echo the Dieselgate.
This attitude reflects his convictions on the ethics of aviation in the face of the climate crisis and indirectly led to his being ousted from his post at the Institute for World Economics in Kiel.
Field research in Papua New Guinea had been extended due to unforeseen circumstances, so the institute had asked him to return within ten days or face dismissal.
Subsequently, on 10 January 2025, the Kiel Labour Court handed down its verdict: the institute would compensate the researcher, but would not re-employ him, on the grounds of ‘incompatibility of the parties' ideological convictions’. "