Specialist in the field of environmental protection, academic teacher, professor at the Faculty of Chemistry at the University of Gdańsk. In the 2016-2020 term, vice-rector, and in the years 2020-2024, rector of the University of Gdansk.

From the beginning of his academic career, he has been associated with the University of Gdansk, where he graduated from the inter-faculty field of Environmental Protection in 1995. In 2010 he was awarded the title of professor of chemical sciences.

Professor Stepnowski is a world-class pioneer of research into the detection and assessment of environmental risk posed by atypical chemical pollutants such as residues of medication or so-called ionic liquids – the modern industrial solvents. Professor Stepnowski cooperates with a wide group of scientists, also from foreign research centers including Germany, France or Portugal.

On November 23, 2020, he was elected rector of the University of Gdansk for the 2020–2024 term. In 2022, he was awarded the medal of the National Education Commission.