Really good GPA though for a first-timer in the American system - I am myself! Here on academic exchange, originally from SciencesPo! Applying for a PhD at University of Toronto.
Tu suis un magistere sur un an, lequel ? Ca fait plaisir de retrouver un Francais ici.
Since your research specifically looks at security as related with climate change, why won't you look primarily at departments that are strong in International Relations (rather than hard-line Political Science), say MIT, Michigan/Ann Arbor, UC/San Diego?