Mark Watts is Executive Director of C40 Cities, a global network of nearly 100 mayors of the world’s leading cities united in confronting the climate crisis. C40 cities represent 25% of global GDP and hundreds of millions of residents.

Named as a TIME100 climate leader in 2023, Mark helped establish C40 in 2005 during his time in London city government, and was appointed Executive Director of the organisation in 2013. Since then, C40 has grown rapidly in scope and ambition. Under his leadership, C40’s 400+ global staff are focused on showing through city leadership how the world can halve global fossil fuel use by 2030 while creating millions of good green jobs and reducing inequality.

Mark was previously a director of the pioneering consultancy firm Arup’s energy and climate team, and before that was the climate and sustainable transport adviser to the Mayor of London.