Sebastián holds an LL.B. and an M.Sc. in geography from the Universidad de Los Andes. He is also a Ph.D. candidate in environmental science, policy & management at the University of California, Berkeley.

He has worked as a researcher at the Center for Socio-legal Research (CIJUS) of the Universidad de Los Andes, lectured in environmental law at the universities of Los Andes and Rosario, and has consulted for different national and international organizations on environmental policy issues.

He has worked on topics such as environment and land use, extractive industries, chemicals governance, the politics of environmental knowledge and technologies, among others.

He currently directs the Environmental Justice area at Dejusticia.