John Clark taught chemistry, physics, and environmental science at Deltona High School in Deltona, Florida since 2006. John is also the science fair coordinator and coach of the Science Olympiad and Physics Bowl teams. He worked with the local community to raise over $550,000 to recognize and promote student excellence in science, and serves as the Treasurer of the School Advisory Council, the school's equivalent of a Board of Directors. John is also involved at the local and national level in the development of standards and curriculum designed to raise student achievement in science and promote careers in science related fields. He has shared his innovative lesson plans and teaching strategies at over a dozen science related conferences around the country. During his summers, John expanded his teaching skills by taking part in academic and research fellowships at Cornell University, the National High Magnetic Field Lab, the University of Missouri, and Jefferson National Labs. By participating in the Teachers for Global Classrooms Program, John was able to develop a Global Classroom Initiative for the students in his school district.

John Clark is huge proponent of global education. He believes that students should be aware of how global structures affect their future because it will prepare them for success. Moreover, he strongly believes that global education can be implemented to more classrooms, schools, and districts by the concerted effort of dedicated leader teachers like himself. John provides educators with a global unit plan on Nuclear Energy. He prompts to students to develop methods that nuclear power can be utilized to address increasing global demands for electrical power in both developed and developing nations. In his global unit plan, he connects his students in Florida to students in India to discuss the potential societal and economic benefits of using nuclear energy to address energy concerns. John traveled to Colombia for his International Field Experience and includes a collection of resources on his travel blog.