Greenhouse gases emitted anywhere affect people everywhere, and they will do so for a very long time. Progress on an international response to climate change has been bedeviled by ethical, political, and economic fractures, highlighting the severe limitations of the Westphalian state system. Non-state actors have played a crucial role in negotiations; some are “internationalist,” whereas others are “globalist.” Climate change is inseparable from capitalism’s insatiable appetite for growth. The rise of China destabilizes previous understandings of the world, including those of global studies and world-systems analysis. There are signs of a new cosmopolitanism, although securitization of the climate threat works against it. The globality of the natural world calls for a rethinking of global studies.