IBF as the Inverse of Event-Based Storylines

Wed, 28 Jan 2026 00:00:00 +0000

Introduction

Impact-Based Forecasting (IBF) and event-based storylines both connect hazard to impact, but they travel the impact chain in opposite directions. IBF reasons forward, starting from a forecast and propagating it through exposure and vulnerability to estimate likely impacts. Event-based storylines reason backward, starting from an event or impact of interest and reconstructing the chain of conditions that produced it.

Forward Direction: Impact-Based Forecasting

IBF begins with a probabilistic forecast of a hazard and asks: given this forecast, what impacts are likely, and what actions should follow? It is anticipatory and operational, driving triggers, thresholds, and early action ahead of an event.

Backward Direction: Event-Based Storylines

Event-based storylines invert this logic. They begin with a plausible or observed event and ask: what combination of drivers, exposure, and vulnerability would lead here? This narrative, conditional framing is useful for planning, learning, and stress-testing, exploring how an event could unfold rather than forecasting whether it will.

Why the Contrast Matters

Treating IBF and storylines as inverse views of the same impact chain clarifies their complementary roles: IBF for real-time anticipatory action, storylines for scenario exploration and decision-centric verification. Used together, the forward and backward perspectives reinforce one another across the forecasting and preparedness cycle.

Climate Scenario and Event-Based Storylines

Tue, 21 Jan 2025 00:00:00 +0000

Introduction

Climate scenarios describe plausible future states of the climate system under different assumptions, while event-based storylines provide a physically self-consistent narrative of how a specific event could unfold. Together they offer a structured way to connect climate science to preparedness decisions under uncertainty.

Climate Scenarios

Scenarios explore the range of possible futures by varying drivers such as emissions pathways, socio-economic conditions, and exposure. Rather than predicting a single outcome, they bound the space of what could happen, helping decision-makers stress-test plans against a spectrum of conditions.

Event-Based Storylines

Event-based storylines, as proposed by Sillmann et al. (2021), link climate projections to preparedness decisions by tracing a coherent chain of cause and effect for a specific event. They map impact chains across scales, offering a credible narrative for handling both direct and indirect impacts while maintaining scientific rigor. This approach complements scenario analysis by grounding abstract projections in concrete, actionable event narratives.

Event-Based-Storylines | E4DRR

IBF as the Inverse of Event-Based Storylines

Introduction

Forward Direction: Impact-Based Forecasting

Backward Direction: Event-Based Storylines

Why the Contrast Matters

Climate Scenario and Event-Based Storylines

Introduction

Climate Scenarios

Event-Based Storylines