The notion of 'planetary boundaries' is rapidly diffusing into a range of policy arenas and has clearly stimulated a discussion on the need to reform international environmental governance. This article summarizes the special section "Global Environmental Governance and Planetary Boundaries". The articles in this section highlight several dimensions for the governance of 'planetary boundaries' and offer a rich picture of the Earth system governance challenges ahead. In essence, these involve exploring issues such as institutional interactions, policy integration, network governance and polycentric coordination in settings where biophysical complexity and non-linear shifts are the rule, rather than the exception. © 2012 Elsevier B.V.