This chapter also addresses concerns about the outcomes of compact city policies and presents ways for policy makers to handle this complex issue. While it appears clear that compact city policies can be expected to play a role in meeting this goal in today’s urban contexts (Chapter 1), an important question for policy makers is: how, and to what extent, can compact city policies be expected contribute to urban sustainability? While there is some evidence concerning energy consumption and the reduction of carbon emissions, there is extensive debate over whether compact city policies have solid, positive effects on environmental quality.