A pioneer for outdoor education in Canada, Charles has embraced the concept of Education for Sustainable Development (ESD) and has played a key role in implementing it internationally. ESD empowers learners to take informed decisions and responsible actions for environmental integrity, economic viability, and a just society, for present and future generations. Today, ESD is globally recognized as a key enabler of the UN Sustainable Development Goals. Charles first introduced innovative education approaches, embedding sustainability concerns in the late 1970s. He has lectured in more than 70 countries and serves UNESCO with research-based policy advice. He is the Co-Director of the Asia-Pacific Institute on ESD (China) and Advisor to the Global Network of Regional Centres of Expertise on ESD with 181 centres globally.