The identity concept has emerged as a key analytical concept in the social sciences in the past decades. In both scientifi c accounts and everyday use, the identity concept has tradi- tionally been seen as something that individuals possess. This view has however been heavily criticized by a social identity strand of social science, where identity is a matter of a negotiation where different social roles are learned in relations with others. The relational view of identities creates some serious problems for the sustainability challenge. In a world of relational identities, individuals are engaged in identity-creating interactions every day. Key problems are that the interactions, in urban environments, are highly commercialized; consumption cues are emotionally based and speak to our senses, and outnumber the competing cues several times over. Sustainable lifestyles are thus very fragile.