How life cycle greenhouse gas emissions change with metrics at urban scale and national scale

Cities are responsible for 75% to 80% of all emissions [1] in the world, and policies that target emissions reductions are often implemented at urban or national scale. We have reviewed several case studies which attempted to quantify greenhouse gases at the urban and national scale. Finding how life cycle greenhouse gas emissions change with respect to various metrics would help policymakers to set new regulations and improve sustainable decision making at urban and national scale.