Global footprint and sustainability

The IPAT equation provides a simple but powerful model for understanding the roles of population, affluence and technology, particularly from the challenge posed by the Anthropocene – how to reduce one’s personal or societal impact.

It takes an actor’s perspective, liberating the question of reducing impact from a technical to a behavioural one; i.e. “how much do I need to change to achieve sustainability?” The model helps by offering multiple pathways, through stabilizing or reducing population, affluence and/or technology or material use, helping to build trust and confidence among actors to support collective action.

Read the paper and supplementary material below, or at the publisher’s site here – and contribute to comments and review of the concepts in this open online review process.



Main article

A ‘preprint’ is a pre-review version of a paper. For information, visit the publisher’s page here.

Supporting articles

Online Supplementary material –

Blog article on the role of Technology in IPAT – on the Millennium Alliance for Humanity and the Biosphere (MAHB) blog.


In the near future, blogs on Population and Affluence will be added.

Graphical abstract