Prof Mark Howden is Director of the Climate Change Institute at the Australian National University. His work has focussed on climate impacts and adaptation for systems we value: agriculture and food security, the natural resource base, ecosystems and biodiversity, energy, water and urban systems. He helped develop the national and international greenhouse gas inventories and has assessed sustainable ways to reduce emissions. Mark has partnered with many industry, community and policy groups via both research and science-policy roles and has over 400 publications. He has been a major contributor to the IPCC since 1991 now being a Vice Chair of IPCC Working Group 2.