When the unlikely becomes plausible : Extending scenario conceptualization to the unexpected event

オコラナカッタ　サイガイ　ニ　カンスル　ケンキュウ　ボウサイガク　ニ　オケル　ＩＦ　ノ　コウヨウ　ニ　ツイテ

ヤモリ, カツヤ

Yamori, Katsuya

サイガイ　ト　キョウセイ　ケンキュウカイ

想定外

必然性

可能性

アンサンブル予測

if

unexpectedness

inevitability

contingency

ensemble forecasting

It is said that there is no “if” in history, but disaster science requires “if” thinking in developing scenarios for disaster planning. This is because the fact-centered stance that has dominated disaster science to date has a major weakness, especially when it comes to “unprecedented” or “unexpected” disasters, in other words, disasters that have not previously been conceptualized (or factualized) as realistic possibilities. Therefore, the aim of this paper is to demonstrate an approach for introducing “if” thinking into disaster science productively by moving from the first stage, where a fact-centered attitude is dominant, through the second stage, which is characterized by multiple possible scenarios symbolized by the large number of paths in ensemble forecasting, to the third stage, where the remaining “unrealistic possibility” is shown to be a “realistic possibility” after making careful and detailed analyses of disasters, with special attention paid to the singularity and specificities of such events. It was also pointed out that reconsidering the fact-centered stance of disaster science does not necessarily mean that facts should be denied, but rather that facts can be utilized more productively by introducing “if” thinking.