Quantifying the influence of global warming on unprecedented extreme climate events

TLDR

Extreme climate events have risen worldwide, and growing efforts to attribute individual events to global warming suggest operational, real‑time attribution may be feasible. The study uses four attribution metrics applied to four climate variables across a global grid. Historical global warming has amplified the severity and likelihood of extreme heat events over 80 % of the globe and increased the probability of extreme droughts and floods in about half the area, indicating that durable operational attribution is achievable yet requires careful diagnosis of individual events.

Abstract

Significance Extreme climate events have increased in many regions. Efforts to test the influence of global warming on individual events have also increased, raising the possibility of operational, real-time, single-event attribution. We apply four attribution metrics to four climate variables at each available point on a global grid. We find that historical global warming has increased the severity and probability of the hottest monthly and daily events at more than 80% of the observed area and has increased the probability of the driest and wettest events at approximately half of the observed area. Our results suggest that scientifically durable operational attribution is possible but they also highlight the importance of carefully diagnosing and testing the physical causes of individual events.