Ban Ki-moon is a South Korean diplomat who was the eighth Secretary-General of the United Nations (UNSG) from January 2007 to December 2016. Before becoming UNSG, Mr. Ban was a career diplomat in South Korea’s Ministry of Foreign Affairs and in the United Nations. As the eighth UNSG, Ban Ki-moon's priorities were to mobilize world leaders around a set of new global challenges, from climate change and economic upheaval to pandemics and increasing pressures involving food, energy, and water. He led the efforts for the landmark Paris Climate Agreement and, under his leadership, the Sustainable Development Goals (SDGs) and the 2030 Agenda were created. Ban Ki-moon currently serves as the Co-Chair of the Ban Ki-moon Centre for Global Citizens which seeks to empower youth and women to become active global citizens in creating a sustainable future for all. In addition, he currently holds over 20 positions, including the Presidency and the Chairmanship of the Global Green Growth Institute (GGGI), and Chairmanships of the Global Commission on Adaptation, the Ethics Commission of the International Olympic Committee, and the BOAO Forum in Asia.

Dr Tim Gregory is a nuclear chemist working in the heart of the British nuclear industry. His work takes him to the forefront of nuclear energy, net zero, nuclear medicine, and space power. Tim is also an author, TV presenter, and prolific public speaker. His books Going Nuclear: How the Atom Will Save the World and Meteorite: How Stones from Outer Space Made Our World were published to critical acclaim. In 2017, Tim surpassed thousands of applicants for a place in the six-part BBC2 series Astronauts: Do You Have What It Takes? where he was put through the full rigours of astronaut selection and reached the final three. Since then, he has gone on to present on BBC4’s The Sky at Night and has made appearances on Steph’s Packed Lunch, BBC Bitesize, BBC Breakfast, BBC Look North, BBC Points West, Sky News Australia, Channel 4 News, and the Norwegian Broadcast Corporation. He frequently features on local and national radio. Tim loves nothing more than sharing his love of science. He frequently speaks to audiences of all sizes and ages – from schools, to corporates, to lecturing at the Royal Institution - on topics including nuclear science, chemistry, planetary science, and the importance of science in society. His enthusiasm is infectious and his deep knowledge shines through.

Christiana Figueres is a Costa Rican citizen and was the Executive Secretary of the United Nations Framework Convention on Climate Change 2010 - 2016. During her tenure, Ms. Figueres brought together national and sub-national governments, corporations and activists, women’s groups, scientists and spiritual communities, financial institutions and NGOs to jointly deliver the historic 2015 Paris Agreement on Climate Change. Under this Agreement, 195 sovereign governments decided on a collaborative path to limit future global warming to well below 2°C, and strive for 1.5°C in order to protect the most vulnerable in every nation. For this achievement Ms. Figueres has been credited with forging a new brand of collaborative diplomacy and received multiple awards. Since then Ms. Figueres has continued to foster rapid action on climate change. She is the co-author of The Future We Choose, The Stubborn Optimist's Guide to the Climate Crisis (Penguin Random House 2019) and co-host of the popular podcast Outrage and Optimism. She is a graduate of Swarthmore College and the London School of Economics and has been awarded multiple honorary doctorate degrees from academic institutions such as Yale, University of Massachusetts, Georgetown and University of Edinburgh. After decades of living and working abroad, she has moved back to her beloved Costa Rica. She has two fantastic daughters, Naima and Yihana, fountains of much joy.