August 14, 2018

expert reaction to statistical model prediction of an ‘anomalously warm’ 2018-2022

A modelling study published in Nature Communications produced predictions of global mean surface air temperature, and suggested 2018 to 2022 was predicted to be an ‘anomalously warm’.

Prof Gabi Hegerl FRS, Professor of Climate System Science at the University of Edinburgh, said:

“The authors have tried to predict whether global climate variability will make the next years warmer or cooler overall than the mean warming trend. They have skilfully used worldwide climate model data for previous years to calculate probabilities for the next few years.

“The findings suggest it’s more likely we’ll get warmer years than expected in the next few years.  But their method is purely statistical, so it’s important to see what climate models predict based on everything we know about the atmosphere and the oceans. Those are more expensive to run but also use more climate physics and observational information.

“These new predictions are not geared up at the moment to predict regional trends such as the hot summer this year; so they may predict how likely it is to have a global record warm year, but not a regional record summer like we’ve had in the UK.”

Professor Adam Scaife, Head of Long Range Prediction at the Met Office, said:

“Empirical models like this can make quite successful predictions of global temperature and they can serve as useful benchmarks to help understanding.  However, global average temperatures are only loosely connected to the year to year variations in regional conditions like the heat waves and dry conditions we have seen this summer, so these simple empirical models are no replacement for more comprehensive models based on the laws of physics which can simulate and predict consistent changes in regional weather.”

* ‘A novel probabilistic forecast system predicting anomalously warm 2018-2022 reinforcing the long-term global warming trend’ by Florian Sévellec & Sybren S. Drijfhout was published in Nature Communications on Tuesday 14 August 2018. 

Declared interests

None received.