This is a joint lecture with INET Oxford In this talk Professor Daniel Kammen, Oxford Martin Visiting Fellow at INET Oxford, will discuss the strategies emerging to cost-effectively decarbonise energy systems worldwide. This work integrates elements of the science and engineering of energy systems, regional and global energy and environmental policy, and mandates and mission objectives that have emerged from the Breakthrough Energy Coalition, and energy and climate planning in both developed and developing nations. As Science Envoy for the US Secretary of State, Kammen will also examine opportunities that have arisen as result of the Paris Climate Accord, and US and Chinese climate agreement. Oxford Martin School, University of Oxford www.oxfordmartin.ox.ac.uk