Backcasting: designing the path from the future you want

Forecasting or walking backward

Most planning looks forward: it starts from the present and projects what will probably happen. That is forecasting. Backcasting reverses the direction: it first describes a desired future and then asks what would have to happen, step by step, to get there from today.

It is useful when the future we want is very different from the one that seems likely, because it forces us to imagine changes a projection would not show.

Where it comes from

The term was proposed by John B. Robinson in the early 1980s, in studies on the future of energy. Since then it has been used in sustainability, urban planning and public policy: for example, to imagine zero-emission cities or water systems for future generations.

Step by step

• Describe the desired future in a specific year, in detail: what you see, what people do, what no longer exists.
• Write down how it differs from the present: what would have to change.
• Walk backward: what would have had to happen five years earlier? And five years before that?
• Identify the milestones and key decisions along that path.
• Come back to the present: what first step can be taken this year?

An example

Imagine that in 2045 your neighborhood has no trash on the streets and almost everything is reused. Walking backward: in 2040 there are repair points in every market; in 2035, separate collection of organic waste; in 2030, schools compost and the first repair workshops appear. And today? Perhaps it is enough to map who already repairs or recycles in the neighborhood and bring those people together.

Backcasting and signals

Signals of change help in both directions. When imagining the desired future, a signal can show that part of it already exists on a small scale. And when walking backward, signals tell us whether we are moving toward that future or away from it.