I have arrived in Copenhagen and my first impression is most favorable. Like a lot of visitors and participants in COP15, I immediately noticed how “livable” this city is. A clean beautiful train whisks you from the airport to Central Station where numerous hotels are within walking distance. In an attempt to shake off my jet lag, I walked down the Stroget, Copenhagen’s 3 kilometer pedestrian-only shopping street.

From there I jumped on the Metro train for a 5 minute ride to the Forum where the Bright Green Expo was taking place. Throughout the afternoon I was amazed to see packs of bicyclists traveling everywhere, utilizing dedicated lanes in many instances and seemingly oblivious to the 0°C temperature!

This brief experience with Copenhagen made me think about what makes a sustainable city? By some accounts, over 50% of the world’s population lives in cities and represent over 80% of carbon emissions.

Many of the key features of a sustainable city are obviously on display here: easy, clean and low-carbon transportation; relatively dense housing and amenities; public spaces for recreation, etc. SustainLane has ranked U.S. cities on these attributes and some Mayors are famously competing for the title of “most” sustainable. Many from around the world are gathering here for the three-day Copenhagen Climate Summit for Mayors. In fact, it is quite encouraging to see “sub-national” governments (as states and cities are known here) forging ahead with climate action plans even as the overall conference seems stalled out in many respects. More tomorrow as I plunge into the COP15 maelstrom!