By its nature, the discipline of human computer interaction must take into consideration the issues that are most pertinent to humans. We believe that the CHI community faces an unanswered challenge in the creation of interactive systems: environmental sustainability. For example, climate scientists argue that the most serious consequences of climate change can be averted, but only if fundamental changes are made. The goal of this SIG is to raise awareness of these issues in the CHI community and to start a conversation about the possibilities and responsibilities we have to address issues of sustainability. Keywords Sustainability, energy use, resource consumption, Value Sensitive Design ACM Classification Keywords H5.m. Information interfaces and presentation: Miscellaneous. K4.0 Computers and Society: General