Dr. Holst has devised advocacy programs addressing human rights, environmental and social justice issues in the United States, the West African Sahara, the jungles of southeast Asia, and the highlands and lowlands of the Andes-Amazon region in Latin America. His work has focused on environmental justice, human rights reporting and advocacy, microfinance reform, emergency relief, youth homelessness, and human trafficking.

He is an applied visual anthropologist, consulting for nonprofits and government agencies, directing documentaries, and publishing articles on humanitarian issues.

His body of work includes:
Political Practice
— Recovering democracy with the help of social movements
Environment
— The intersection of violent conflict and environmental issues
— Insights on sustainability from indigenous communities in the Amazon
— Environmental justice in the US, Latin America, and Southeast Asia
Inequality
— Micro-finance reform
— Social protection and emergency relief