Dennis is a former UN Youth Representative for Sustainable Development. In this role, he has been a member of the Dutch delegation to, among others, the COP26 climate summit in Scotland and COP27 in Egypt. Speaking to thousands of young people is the basis for properly representing the voice of young people within the government delegation, in conversations with high-level officials and speeches at national and international levels. Furthermore, Dennis fulfils his role as a youth representative with a specific emphasis on climate justice. He does this, among other things, as a campaigner for the worldwide youth movement World’s Youth for Climate Justice. This movement is committed to obtaining an advisory opinion from the International Court of Justice on human rights and climate. Dennis is also active in the RIVM’s societal sounding board. Dennis is also pursuing a master’s degree in sustainable business & innovation at Utrecht University.