The two-word definition of sustainability is 'one planet.'

- Mathis Wackernagel

We have to prepare our cities for the increasing scarcity of resources by increasing their density and energy efficiency.

- Mathis Wackernagel

Humanity is living off its ecological credit card and can only do this by liquidating the planet's natural resources.

- Mathis Wackernagel

Pain is not an evolutionary error.

- Mathis Wackernagel