We're hearing more and more about cities and their roles in sustainability. But amidst that rising discussion, how can we build opportunities to ensure some real success for sustainable development in an urban world?

In October, the Habitat III conference on urbanization resulted in the adoption of a 20-year strategy on sustainable cities. That document, the New Urban Agenda, promotes cities as positive forces for sustainable development. This recognition alone constitutes an important paradigm shift.

Nevertheless, the New Urban Agenda falls short on two challenges.

First, it fails to adequately harmonize with the global agreements struck in 2015, particularly the Sustainable Development Goals (SDGs), the Paris Agreement on climate, and the Addis Ababa Action Agenda on financing for development. Together, these agreements will guide global sustainability efforts towards 2030 – what's collectively known as Agenda 2030. This gap in the New Urban Agenda is problematic given that Habitat III was being seen as an opportunity to "localize" the SDGs in cities.