TECH FOCUS:SUSTAINABLE ENERGY TECHNOLOGY The actual system boundary for mobility impact. SUSTAINABLE MOBILITY It's not just going electric. What do we mean when we talk about sustainable mobility? Do we just look at the local energy and emissions balance at the vehicle? Do we look at the local grid level? National? Global? How we choose to define the problem dramatically changes what kinds of engineering and social solutions we can include in any attempt to achieve sustainability. And since the sustainability conversation usually centers on greenhouse gas emissions, the only sensible problem definition is global, as a locally-focused " solution " can easily do more harm than UPDATE good on a global scale if we don't look at the whole problem. As an individual, we are prone to looking at the smallest possible system boundary: our car that we drive. So an EV looks extremely sustainable if we simply assume renewable electricity for the input, and there are no negative outputs. But as engineers we know that the boundary is larger. Even for that single vehicle we need to include the inputs to build it, the end of life waste, and the real electrical grid mix. In other words, we need to use life-cycle analysis (LCA) to October 2022 7 SwRI