One of the problems with scenario planning is that it requires plausible scenarios, but that reality is behaves in ways that are implausible.  This is another way of describing what Nassim Taleb named Black Swans, significant unexpected events, that change the course of events in unlikely ways.
In an article in the International Herald Tribune magazine, well known Japanese novelist Haruki Murakami, author of the Windup Bird Chronicle and many other books, about how he believes that ‘realistic’ fiction is now incapable of capturing the present.  In his article Reality A and Reality B Murakami writes:
Over the past 30 years, I have written fiction in various forms ranging  from short stories to full-length novels. The story has always been one  of the most fundamental human concepts. While each story is unique, it  functions for the most part as something that can be shared and  exchanged with others. That is one of the things that gives a story its  meaning. Stories change form freely as they inhale the air of each new  age. In principle a medium of cultural transmission, stories are highly  variable when it comes to the mode of presentation they employ. Like  skilled fashion designers, we novelists clothe stories, as they change  shape from day to day, in words suited to their figures.
Viewed from such a professional perspective, it would seem that the  interface between us and the stories we encounter underwent a greater  change than ever before at some point when the world crossed (or began  to cross) the millennial threshold. Whether this was a change for the  good or a less welcome change, I am in no position to judge. About all I  can say is that we can probably never go back to where we started.
Speaking for myself, one of the reasons I feel this so strongly is the  fact that the fiction I write is itself undergoing a perceptible  transformation. The stories inside me are steadily changing form as they  inhale the new atmosphere. I can clearly feel the movement happening  inside my body. Also happening at the same time, I can see, is a  substantial change in the way readers are receiving the fiction I write.
There has been an especially noteworthy change in the posture of  European and American readers. Until now, my novels could be seen in  20th-century terms, that is, to be entering their minds through such  doorways as “post-modernism” or “magic realism” or “Orientalism”; but  from around the time that people welcomed the new century, they  gradually began to remove the framework of such “isms” and accept the  worlds of my stories more nearly as-is. I had a strong sense of this  shift whenever I visited Europe and America. It seemed to me that people  were accepting my stories in toto — stories that are chaotic in many  cases, missing logicality at times, and in which the composition of  reality has been rearranged. Rather than analyzing the chaos within my  stories, they seem to have begun conceiving a new interest in the very  task of how best to take them in.
By contrast, general readers in Asian countries never had any need for  the doorway of literary theory when they read my fiction. Most Asian  people who took it upon themselves to read my works apparently accepted  the stories I wrote as relatively “natural” from the outset. First came  the acceptance, and then (if necessary) came the analysis. In most cases  in the West, however, with some variation, the logical parsing came  before the acceptance. Such differences between East and West, however,  appear to be fading with the passing years as each influences the other.
…
We often wonder what it would have been like if 9/11had never happened —  or at least if that plan had not succeeded so perfectly. Then the world  would have been very different from what it is now. America might have  had a different president (a major possibility), and the Iraq and  Afghanistan wars might never have happened (an even greater  possibility).
Let’s call the world we actually have now Reality A and the world that  we might have had if 9/11 had never happened Reality B. Then we can’t  help but notice that the world of Reality B appears to be realer and  more rational than the world of Reality A. To put it in different terms,  we are living a world that has an even lower level of reality than the  unreal world. What can we possibly call this if not “chaos”?
What kind of meaning can fiction have in an age like this? What kind of  purpose can it serve? In an age when reality is insufficiently real, how  much reality can a fictional story possess?
…In that sense, at the same time that fiction (story) is presently  undergoing a severe test, it possesses an unprecedented opportunity. Of  course fiction has always been assigned responsibility and questions to  deal with in every age, but surely the responsibility and questions are  especially great now. Story has a function that it alone can perform,  and that is to “turn everything into a story.” To transform the things  and events around us into the metaphor of the story form and to suggest  the true nature of the situation in the dynamism of that substitution:  that is story’s most important function.
Biologist and British science fiction writer Paul McAuley, author of the very good the Quiet War and Gardens of the Sun, reflect on how science fiction has largely failed to engage the world Murakami evokes but has the potential to do so in his  response to Murakami’s article: 
As a science-fiction writer, I find Murakami’s ideas incredibly interesting. And hopeful. Or rather, potentially hopeful. For something similar should have happened to science fiction, shouldn’t it? After all, catastrophes and sudden shifts in perception are part of its stock in trade. But instead of confronting Reality A, the genre has, in the first decade of the 21st century, too often turned to its own comforting version of Reality B: retreating into pleasant little pulpish daydreams in which starships still effortlessly span a galaxy where a guy can turn a profit, or where technology is as controllable as clockwork and the actions of individuals can still make a mark on history. Meanwhile, they grumble, ‘mainstream’ writers are grabbing ideas from the genre and doing terrible things to them without acknowledging the source. As if permission could be somehow given, or withheld.
I prefer the point of view of William Gibson, who has pointed out that the only way to tackle the place we’re in now is to use the science-fiction toolkit – the tropes, images and metaphor developed from the crude flint hammers of pulp by decades of cooperative effort and argument. If other writers are using the science-fiction toolkit to evolve new kinds of stories in the present’s different air, that’s exactly what we should be doing, too. Forget the past. Especially the pasts of all those great glorious science-fiction futures, lost when it all changed. Look again at the future. Embrace change. Let go. If only. If only.