David Miller, the former mayor of Toronto and previous chair of the C40 Cities Climate Leadership Group, delivered the keynote address late last week at a Munk School conference on de-carbonization and the future of climate governance.

Miller has been at the forefront of a movement suggesting that cities, rather than nations, can be prime movers for environmental sustainability. “Nations merely talk about climate policies and accomplish very little change overall,” said Miller. “By comparison, cities – especially those governed by progressive mayors – are capable of taking more decisive action.”

The main reason why mayors are acting, Miller suggested, is because there is so much pressure for them to do so. In the wake of 2012’s string of record-breaking droughts and hurricanes, mayors are expected to both react to and postpone these increasingly dangerous natural disasters. The best way to do both, says Miller, is to promote sustainable through progressive urban planning, development, and infrastructure.

Of particular interest for Miller are city initiatives that attempt to overcome the environmental drawbacks of generating electricity, heating and cooling buildings, and inefficient transportation systems. An emphasis is placed on these three sectors because of their importance in city management. He also suggests that projects in these sectors aid both the environment and the economy because of how they increase efficiency and promote jobs in a safe and sustainable manner.

Miller concluded his speech by suggesting that citizens are also able to make a difference. Thinking locally, progressive activists are capable of generating the movement necessary to create change. In the same vein, Miller believes that mayors, acting cooperatively to create a unified voice, can also affect global climate change policies.