Cite as: C.A. Kennedy, S. Demoulin, E. Mohareb, 2012. Cities reducing their greenhouse gas emissions. Energy Policy, 49, pp. 774–777 1 Cities Reducing Their Greenhouse Gas Emissions Christopher Kennedy, Stephanie Demoulin, Eugene Mohareb Affiliation of authors: Department of Civil Engineering, University of Toronto 35 St. George Street, Toronto. M5S 1A4. Tel: 416 978-3674. e-mail: christopher.kennedy@utoronto.ca For several reasons, cities are increasingly seen as critical actors in efforts to counteract global climate change 1-7 . The majority of global greenhouse gas (GHG) emissions can be attributed to the production and consumption activities of cities. Meanwhile, with high concentrations of people and infrastructure, cities are particularly vulnerable to the impacts of climate change. Given also their wealth and potential creativity, cities should be leaders in mitigation of GHG emissions, but just how well are they doing? We find that several major cities are reducing their per capita GHG emissions, primarily through changes to stationary combustion; and in some cases the cities are leading their nation states. To assess their progress in reducing GHG emissions, we examined data from six cities for which repeat GHG emission inventories have been conducted. The six cities: Berlin, Boston, Greater Toronto Area (GTA; comprised of several municipalities), London, New York City (NYC) and Seattle were studied because they have open access inventories, with detailed sectoral information 8-13 . Inventory methodologies differ between cities with respect to the inclusion of scope 3 14 out-of-boundary emissions, including sources