Permit me to ramble while I get my thinking in order. My naive intuition suggests to me that it may not be the time horizon per se that is important in scenario planning, but rather relate-able points/events in future time. For example, for those of us old enough to look back at the lead up to the moon landing, JFK essentially provided a ten year time frame that had a goal associated with it. At the time we thought that horizon was eons away but looking back the time went so quickly. Moreover, few at the time would have imagined the amazingly disparate institutions, disciplines and new lines of inquiry that would eventually become essential to the goal. It wasn't just about astronomy, physics, engineering and aeronautics, but about also about materials science, health and nutrition, neurology, psychiatry etc etc. We know this now, that big challenges throw up curve balls, and we can use this experience when relating forward. For example, I recently asked a bunch of ag science graduates to look at what food production out to the year 2050 might look like. The students looked a bit lost and essentially projected from the pathways we were currently on. So, I threw into the discussion that there was a high probability that we would have our first rockets landing on Mars by around 2030, and potentially first small colonies on Mars by 2050 (even if just colonies of scientists). What would we have to learn about providing food for a remote colony on another planet, and what lessons might we take from that to provide food for space-ship earth? Colonizing Mars is a relate-able event, not least because we lived the moon experience and can already see the coalescence of powerful interests with a goal of colonizing mars. Expecting the unexpected is also relate-able, given the weird, wonderful and unanticipated advances made during the moon missions. Anyway, it makes me think, don't pick a year in future when running scenarios, but pick a relate-able events long into the future to stimulate thinking. Of course, this approach can also close-off lines of thought. Bugger it, ask Steve Cork - he's much better at this sort of thing than me!

Don't forget religious beliefs, which impact how many people (including scientists) view the future :)

Thanks, Richard and Andrew.

Richard - I think time always feels so different looking back than looking forward, but I don't think we ever learn from that experience to do anything but discount the future. I think it is a solid suggestion, however, to anchor scenarios in an event rather than a time: i.e. when sea level rises by X amount, rather than in year Y. This may also get past some of the challenges in setting year Y without wide uncertainty bars.

Has anyone else found the sweet spot, or have clever ways to establish it? In spatial analysis there is a rule that you choose a raster cell size at least half (in each direction) of the smallest thing you want to be able to resolve. Is there a temporal corollary for 'resolving' the future.

Hello, Kate, as you well know, the choice of a time horizon will depend on the results you expect to obtain. In our case, our research focuses on Low Carbon Scenarios, so the scenarios and expected results are planned in the long term, by the year 2050.

Long term is a flexible term. There is a concept attributed to indigenous people in Canada known as Seven Generations. When making decisions, consider how they will impact your grand children's great-grand children. That's in the order of 150 to 200 years.

Thanks, Mariano and Douglas,

So true that ideas of long term vary by discipline and culture. I would think that for many older people, even 2050 would be difficult to really care about or conceptualize. If they do, it may be in extremely techno-optimistic terms; i.e. someone will have figured it out. Seven generations may involve much more magical thinking. Do either of you find that your participants have difficulty thinking in such long terms to the degree that the scenario discussions do not gain traction around shorter term implications? For instance, participants happily commit those future 'others' to livestyles or actions they would never accept themselves?

Every horizon is different, and how people react to it is different. Municipalities are quite happy to discuss 40 year horizons. Most people are wondering about their own life over the next 5 years. Older people may have a better concept of how things have changed in the past, but may have less concern about what'll happen in the future.

When I've had discussions about the future, I tend to assume that tomorrow will be pretty much the same as today, except for the things we intentionally change today. No discount rate, no population growth - none of the stuff that just 'happens'. Then when working on the vision, it's about what the people want for themselves, their children, and their grand children. I've never asked past that - certainly not past the kids' lifetime. I think it would therefore be prudent to have a range of ages and experiences in your discussion group.

I have found that most people have a really hard time contemplating details of a future that is meaningfully different from today, or the distinction between 60 and 100 years from now. The Global Association of Transition Engineers knows that everything we are building today will receive it's first maintenance that in a low-energy-intensity environment (unlike the high-energy-intensity environment we're in right now). That's really hard to explain to clients. It's not 'green' - it's making sure the investment has any value at all in 50 years.

Please Mr Price, not Mars

https://www.youtube.com/watch?v=mrGFEW2Hb2g

I'm with you Peter. Our footprints often end up doing more harm than good! Loved the clip, BTW.

Thanks Christopher Steinman

We're looking for a temporal sweet spot in terms of self-regulation (action is needed, but not fear) and discounting (action sooner will reduce costs later). These are all useful theoretical anchors for our quest. Much appreciated.

Less than 50 years is quite accurate, beyond is not real. Short to medium periods can be useful for producers and policy makers.

There is a Rawlsian approach to this problem suggested decades ago by Talbot Page in his book Conservation and Economic Efficiency. Page suggested that, when dealing with intergenerational issues we use Rawls' "veil of ignorance." That would mean asking participants to address policy issues (with intergenerational implications) as if they were ignorant of their personal characteristics, including their generation. The idea is to try to transcend self interest. Presumably under a veil of ignorance one would adopt a precautionary principle. (Rawls only applied this as a thought experiment to try to reason out the principles of justice.)