Peter is Director of the Land and Resource Rights (LRR) initiative. LRR seeks to strengthen land tenure and natural resource rights of rural people and communities by: 1) conducting research and generating new knowledge on critical property rights issues; 2) developing information platforms, including an online platform to document community rights; 3) participating in and contributing to policy and legislative reform processes; and 4) building the capacity of civil society organizations and other actors. Peter is also a former Adjunct Professor at the School of International Advanced Studies, Johns Hopkins University.

For more than 25 years, Peter has worked on a range of environmental governance matters, particularly environment/democracy and environment/human rights links. He has conducted research and written on community-based natural resource management, environmental decentralization, environmental advocacy, and other environmental accountability matters. Peter has undertaken long-term field research in a number of African countries, including in Sierra Leone as a Fulbright Scholar, where he conducted research on household variability in agricultural strategies and practices; and, in Rwanda as Director of the Karisoke Mountain Gorilla Research Center, where in the 1970s he studied the behavior of mountain gorillas. Peter has also held a range of research and teaching positions at the University of California campuses at Santa Cruz and Davis.