Ecologically-friendly lifestyles such as Minimalism—living with less—are gaining attention in popular media outlets. However, it is unclear whether ecological concern is driving the popularity of these lifestyles, and how social marketing campaigns could leverage this consumer shift. This research examines whether living with less is equally encouraged by biospheric and egoistic appeals, e.g., reducing carbon emissions and reducing stress, respectively. In an initial exploratory study (N = 265), self-described minimalists reported both biospheric and egoistic concerns as likely to motivate a minimalistic lifestyle. However, in an experimental setting (Study 1; N = 296), biospheric appeals were ineffective in shifting consumption-curtailment engagement, even for highly biospheric participants. The ineffectiveness of biospheric appeals was not explained by value incongruence, presenter relatability, negative affect, perceived self-efficacy or control. The real-world impact of egoistic and biospheric consumption-curtailment appeals was also tested in a week-long online intervention (Study 2; N = 102). The biospheric appeal presented null effects as compared to a control condition, while the egoistic appeal increased participants’ motivation to curtail their consumption. Results suggest that biospheric appeals for consumption curtailment may be ineffective. Limitations and directions for future research, as well as implications for social-marketing practice, are discussed.