^^Abstract:^^

Over the past 2-4 years, the international climate science community has converged on a small number of major challenges that, if confronted over the coming decade, would advance our understanding of the Earth system in a number of important ways. These 'Grand Challenges' are now filtering down into various activities, including the planning for the IPCC AR6, and more recently into preliminary strategic thinking for future Earth Observational systems. The science questions that underpin these GCs will be highlighted and recommendations stemming from the recent Climate Symposium will be discussed. Emerging national activities, some being much closer to JPL and the labs interests, will also be discussed.

^^Bio:^^

Graeme Stephens is the current Director of the Center for Climate Sciences at JPL and is co-chair of the Global Energy and Water Exchange (GEWEX) Program of the World Climate Research Program.