Environmental migration is often presented as one of the gravest consequences of environmental disruptions – climate change in particular, and is already a reality in many parts of the world. Yet the protection of these migrants is not adequately addressed in the international normative frameworks on migration. As a result, a growing number of scholars and advocacy groups have sought to create a special convention and/or an ad hoc status for these migrants, while others have contended that such a legal status is not the answer. As a result, the protection of environmental migrants is currently the subject of vigorous debates amongst scholars and policy-makers, and no clear solution is yet in sight. Research however has little considered the debates that surrounded the protection of those displaced within their countries (IDPs) in the 1990s. Both phenomena have sometimes overlapped, especially as environmental displacement is often internal. Yet, the debate on IDPs has had some significant success, in particular, the adoption of the Guiding Principles on Internal Displacement in 1998, and the signature of the Organization for African Unity’s Kampala Convention in 2009. This article argues that important lessons can be drawn from the protection of IDPs in order to inform the current debates on the protection of environmental migrants, as the political contexts and policy challenges associated with both crises of the migration regime are often similar. The article identifies such lessons and assesses the opportunities and caveats of applying a similar approach of soft law to environmental migration – and what would be needed to achieve it.