Abstract
A safe and just operating space for socioecological systems is a powerful bridging concept in sustainability science. It integrates biophysical earth-system tipping points (ie, thresholds at which small changes can lead to amplifying effects) with social science considerations of distributional equity and justice. Often neglected, however, are the multiple feedback loops between self-identity and planetary boundaries. Environmental degradation can reduce self -identification with nature, leading to decreased pro-environmental behaviours and decreased cooperation with out -groups, further increasing the likelihood of transgressing planetary boundaries. This vicious cycle competes with a virtuous one, where improving environmental quality enhances the integration of nature into self-identity and improves health, thereby facilitating prosocial and pro-environmental behaviour. These behavioural changes can also cascade up to influence social and economic institutions. Given a possible minimum degree of individual self-care to maintain health and prosperity, there would seem to exist an analogous safe and just operating space for self-identity, for which system stewardship for planetary health is crucial.