Tuesday, December 10, 2024

 

Leap in modelling human impact on climate may lead to early warning of climate disasters



Mathematicians led by the University of Leicester have applied statistical mechanics to climate change detection and attribution for first time



University of Leicester

Global temperature map 

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Map showing global temperature anomaly in degrees Celsius caused by doubling the concentration of carbon dioxide over a century.

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Credit: Valerio Lucarini and Mickaël Chekroun




A breakthrough in the theory of climate change science has given scientists the most robust way yet to link observed climate change to both human-made and natural causes and to spot early warning signals for potential climate disasters.

An international collaboration between Valerio Lucarini, a mathematician from the University of Leicester, and scientist Mickaël Chekroun has led to applying principles of statistical mechanics to climate science to frame how to distinguish the climate change signal from the “background noise” of natural climate variability and to flag the nearing of ‘tipping points,’ such as those associated with the collapse of the Atlantic Ocean circulation or of the Amazon forest.

This theoretical advance paves the way for the development of innovative methods to study climate change and its associated risks, thanks to a more advanced understanding the underlying mechanisms driving climate change.

Published in the journal Physical Review Letters, it will give scientists the confidence in performing climate change attribution and to identify when we are on the route to a potential climatic tipping, and to take preventative measures to mitigate against one. It will give policymakers much needed certainty about the procedures used for assessing climate change.

Tipping points are thresholds in our climate system that potentially lead to large scale change and damage to our environment. Events such as the collapse of the Atlantic meridional overturning circulation, a slowdown of which would result in a relative cooling in this region, or the ecological collapse of the Amazon rainforest would have disastrous implications for life on our planet. However, it is difficult to anticipate when we are reaching a potential tipping point from climate data.

The challenge is distinguishing the evidence of climate change and, in particular, an impending tipping point from the natural climate variability that exists. The ‘signal’ of human-caused climate changes is obscured in the ‘noise’ of natural changes in the environment. The Leicester-led team found that the existing approach, based on a purely statistical method, provides limited information about the dynamical processes that affect our climate. It provides a snapshot of our climate, with no insight into how it came to be that way.

By applying the principles of statistical mechanics – the physics behind random dynamical processes - their research instead allows us to turn back the clock on that snapshot and understand how that picture was formed. They created a mathematical model able to recreate dynamically the processes at play and identify the causes of change. From this, they could ‘fingerprint’ the signal of human-caused climate change and determine its impact, allowing a dramatic improvement in the ability to detect early warnings of climatic tipping points.

Lead author Professor Valerio Lucarini from the University of Leicester School of Computing and Mathematical Sciences said: “This problem of how we attribute anthropogenic forcings in climate data has far-reaching consequences. Climate change sceptics have questioned how you can relate a forcing in a system that fluctuates a lot to a specific cause. The climate has always changed and will always change. How do you counter that argument and demonstrate what we're observing now is due to human intervention? Of course, the scientific community has come to strong counterarguments but so far they were exclusively based upon statistical, and not dynamical, arguments.

“The breakthrough we made is in connecting the physics of the system, the laws that determine the evolution of the system, to what you can observe. It's pretty clear from that the best way to study change is in the evolutionary laws that impact what we're observing, and that change would be exactly the climate forcing we are looking for."

Dr Mickaël Chekroun from the University of California, Los Angeles, and the Weizmann Institute of Science added: “This is quite a big step because it tells us that the detection and attribution methods we have used for many years to say that climate change is there are well founded. We show how the methodology can be improved and we can see its potential pitfalls. We have advanced substantially the theory of climate dynamics and of the relationship between climate variability and climate change.”

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Notes to Editors

About the University of Leicester  

The University of Leicester is the Daily Mail University of the Year 2025 and shortlisted for University of the Year for both the Times Higher Education Awards 2024 and the Times and Sunday Times Good University Guide 2025.

The University is led by discovery and innovation – an international centre for excellence renowned for research, teaching and broadening access to higher education. It is among the Top 30 universities in the Times Higher Education (THE)’s Research Excellence Framework (REF) 2021 rankings with 89% of research assessed as world-leading or internationally excellent, with wide-ranging impacts on society, health, culture, and the environment. In 2023, the University received an overall Gold in the Teaching Excellence Framework (TEF) 2023, making it one of a small number of institutions nationally to achieve TEF Gold alongside a top 30 REF performance. The University is home to more than 20,000 students and approximately 4,000 staff.

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