Beate Jessel has been trained as an engineer, landscape ecologist and landscape architect. She initially worked for several years in a planning office and at the Bavarian Academy for Nature Conservation and Landscape Management (ANL), where she was responsible for ecologically oriented planning and was also involved in continuing professional development for adults. After completing her doctorate on the theory of ecologically oriented planning, she was a professor at the University of Potsdam at the Institute for Geoecology and at the Technical University of Munich (Head of the Chair for Strategic Landscape Planning and Management).

In 2007, she was appointed by the German Environment Minister as President of the Federal Agency for Nature Conservation (BfN),  the central federal authority for national and international nature conservation, which enforces nature conservation law at the federal level, advises political decision-makers, provides research results and data, and supervises research projects.
In this role, she was responsible for enforcement tasks in areas such as genetic engineering, species protection and marine nature conservation, for Germany's international nature conservation responsibilities (e.g. the implementation of international conventions), and for the allocation of funding and supervision of applied research projects aimed at implementing nature conservation and providing science-based policy advice.

In 2021, the Swiss Federal Council appointed Beate Jessel as Director of the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), combined with an appointment as Professor at EPFL and ETH Zurich. Since August 2023, she has been fully performing her duties at EPGL as Head of the Laboratory for Landscape Development (LAND).

Beate Jessel holds positions on various advisory boards and committees. She is a member of the Scientific Advisory Board of the Chinese Academy of Environmental Sciences (CRAES) and the University Council of the University of Geisenheim, as well as a member of the editorial boards of the two journals GAIA - Ecological Perspectives for Science and Society and Naturschutz und Landschaftsplanung (Nature Conservation and Landscape Planning).