This paper investigates the contribution of socio-economic scenarios to improve decisions and policies in climate assessments. We specifically looked at adaptation projects in the Dutch Climate changes Spatial Planning programme. Based on the four decision failure criteria neglect of internal information, bounded rationality, insufficient expansion of existing mental models and stickiness and lack of friction of information and knowledge, it was concluded that in these projects, socio-economic scenarios appear to generate useful data, but that their full potential to reduce decision failure is not likely to be exploited. Therefore adaptation options suggested by these studies may not be 'future-proof': they may be appropriate in some future societies, but fail in others. We believe similar results would be obtained in other contexts. Possible decision failures are caused by neglecting socio-economic developments, limiting the number of storylines generated by scenario studies to one or two, lack of stakeholder involvement in the scenario development and ignoring discontinuities. © 2011 Elsevier Ltd.