- Full Professor of Law at the Faculty of Law, University of Leuven (Belgium) (http://www.law.kuleuven.ac.be),
- Expert - Senior Legal Advisor at the Private Office of Mr. Kris Peeters, Minister for Public Works, Energy, Environment and Nature, Flemish Regional Government (Belgium) (http://www.krispeeters.be),
- Visiting Professor of Environmental Law at the European University College Brussels (Belgium) (http://www.ehsal.be), and
- Visiting Professor of Climate Change Law (August 2007) at the Faculty of Law of the National University of Singapore (http://www.law.nus.edu.sg).

He is also:

- Director of the Institute for Environmental and Energy Law, Faculty of Law, University of Leuven (http://www.law.kuleuven.ac.be/imer);
- Co-Founder and Co-Director of the Center for Construction Law, Faculty of Law, University of Leuven (http://www.law.kuleuven.ac.be/bouwrecht);
- Director of the THEMIS-School for Continuing Legal Education (http://www.pvthemis.be);
- Co-Founder and Co-Director of the LLM-Program "Advanced Master of Energy and Environmental Law", Faculty of Law, University of Leuven (http://www.law.kuleuven.ac.be/imer/master);
- Chair of the Department of Public Law, Faculty of Law, University of Leuven (http://www.law.kuleuven.be);
- Academic Co-ordinator of the Erasmus/Socrates Office, Faculty of Law, University of Leuven (http://www.law.kuleuven.be/erasmus).

Finally, he is:

- Program Leader Environmental Law of the Section on Transboundary Environmental Law, Ius Commune Research School (http://www.rechten.unimaas.nl/ozic);
- Co-Director of the Ius Commune Centre for Environmental Law, Ius Commune Research School (http://www.rechten.unimaas.nl/ozic);
- Fellow of the Academy of Environmental Law (http://www.iucn.org/themes/law/cel07a.html);
- (Co-)Promotor of several research projects for the University of Leuven Research Council or the federal, regional and local authorities in Belgium and the Netherlands;
- (Co-)Promoter or member of the promotion commission of PhD's at the University of Leuven and foreign universities;
- (Co-)Author and Editor of books, book contributions and articles in national, European and international reviews.