I think that statement about less clue/relatively little clue is true about nearly every field of active research, including nuclear fusion power, hurricane path and strength prediction, understanding the brain, designing new drugs, and the life of pre-Clovis peoples in the Americas. In 20 years we'll look back and comment about how little we knew of the human genome, or how wildly wrong we were in predicting the effect of autonomous vehicles on daily life.

Also, "relatively little clue" can still enough to make useful decisions. Therefore I ignored it.

Without knowing which consequences, what am I supposed to say? I see no reason to think the Dutch are misspending their money in building up their sea defenses against likely sea level rise.