Sebastian is a research scientist at the Massachusetts Institute of Technology's Laboratory for Aviation and the Environment (LAE). His previous work has covered development and application of global atmospheric chemistry and transport models, ranging from his work to implement stratospheric chemistry in the GEOS-Chem community atmospheric model, through to his recent paper discussing the possible health effects of solar geoengineering. He is currently working as a visiting scientist for the Harvard Solar Geoengineering Research Program, investigating the behavior of aircraft plumes in the stratosphere - including those which would be expected to form if stratospheric aerosol injection were ever deployed.