Water & Climate

Rethinking climate modelling to prepare for even hotter temperatures

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Researchers compared two major climate modelling methods, transient climate where the global temperatures are consistently rising over the next 80 years and equilibrium climate where the temperatures rise and reach a steady equilibrium over the course of centuries.

Published in Nature Climate Change, the study found that, in order to be effective, climate change policies need to take into account the significant differences between transient and equilibrium climate models.

More than 90 per cent of the world’s population would experience higher local temperatures and twice the number of heatwaves as per transient climate modelling compared with equilibrium modelling at the same global temperature.

Globally, emissions and climate change targets, including those set by the 2015 Paris Agreement, are more often based on equilibrium climate models.

Lead researcher Dr Andrew King from the University of Melbourne’s School of Earth Sciences said that it would be more appropriate to also take into account transient modelling to prepare climate change policies for the near future.

“Differences in methods used to simulate future climates could lead to inadequate information and development of ineffective policies,” Dr King said, “especially in building resilience for future extreme heat events.”

The researchers used simulated future worlds to compare the two climate modelling methods.

The transient future climate model showed that the northern hemisphere would experience warmer average temperatures in summer. The researchers also observed that poorer regions of the world had a greater probability of hot seasons.

The study concluded that using multiple modelling methods would more comprehensively help to examine the impacts of the Paris Agreement global warming levels.

“If we manage to implement effective policies and meet the Paris Agreement goals we will benefit from fewer hot summers and, in some populated areas, we should see a reduction in heat extremes relative to the current climate,” Dr King said.

The research was conducted at the University of Melbourne’s School of Earth Sciences and the Australian Research Council (ARC) Centre for Excellence for Climate Research in association with the School of Earth, Atmosphere and Environment at Monash University. The study was funded through ARC research grants.

Source: The University of Melbourne