Beyond living memory: Why past rainfall extremes misrepresent future risk

Abstract

Relying on historical observations of rainfall means we underestimate the risk of future, unprecedented extreme rainfall events across New Zealand. Society tends to adapt only to the most extreme events experienced within living memory, which compounds this problem and leaves communities under-prepared.

This research finds the range of plausible future rainfall events is far wider than the historical record suggests. Decision-makers must plan for extreme rainfall despite this uncertainty, with confidence that events will become more intense and frequent under climate change.