Through community participation in local decision-making, Simmons has helped implement water projects and a number of other activities. Children are taught about conservation in a day-care center. Hundreds of students have been involved in clean-up campaigns and leadership training. The entire community is now committed to ensuring that only environmentally sound development projects be located in the area, and it has organized against destructive projects such as sand mining.
In addition to being an initiator of JEMS, Simmons founded the Caribbean Youth Environment Network (CYEN) and has worked as Director of Community Services for St. Vincent. Through the United Nations Environment Program, Simmons has advised on the development of similar youth programs in other countries. Simmons has also worked as Chief Programme Officer of the Commonwealth Secretariat in London, England, where he works with 54 countries in Asia, the Pacific, Caribbean and African region on the development of programs in the areas of youth policies, human resources development and youth empowerment.
Simmons is currently working on a program that encourages youth and community members to take action against climate change; the biggest threat facing their island nation. Activities include a national week of climate action which took place in October 2015. This program is being supported by the Jewish Community Foundation and the Goldman Environmental Foundation.