The article sets out a "big history" which resonates with the priorities of our own time. A globalizing world calls for new spacial scales to underpin what the history curriculum addresses, "big history" calls for new temporal scales, while concern over climate change calls for a new look at subject boundaries. The article proposes a planet-wide big history which builds on the considerable disciplinary gains made in history education in recent decades as well as proposing a history curriculum with more porous boundaries between natural and human history. What this might look like in classrooms is explored and the limitations and obstacles to the implementation of these approaches in classrooms addressed.