Nobel Prize in Physics 2021 for two climate change experts and an Italian theorist | Description of complex systems and their long-term behavior

The Nobel Prize in Physics 2021 was awarded this Tuesday to two experts in physical modeling of climate change, the Japanese-American Syukuro Manabe and the German Klaus Hasselmann, as well as the Italian theorist Giorgio Parisi.

Half the price will go to Manabe, 80, and Hasselmann, 79, “for physical modeling of the Earth’s climate and for quantifying variability and reliably predicting climate change, ”the jury said.

The other half was attributed to Parisi, 73, “by the discovery of the interplay of disorder and fluctuations in physical systems, from the atomic scale to the planetary scale “.

Understand complex systems

This Nobel recognizes new methods of describing complex systems and predict long-term behavior. One of them, of vital importance to humanity, is the Earth’s climate.

In its argument, the Royal Swedish Academy of Sciences notes that complex systems are characterized by randomness and disorder and are difficult to understand.

“Discoveries recognized this year demonstrate that our knowledge of climate is based on a solid scientific basis, based on a rigorous analysis of the observations, ”said Thors Hans Hansson, chairman of the Nobel Committee for Physics, at the prize-giving press conference.

All of this year’s laureates have contributed – he added – to “a better understanding of the properties and evolution of complex physical systems”.

The discoveries of Manabe and Hasselmann

the Japaneses Manabe, 90, demonstrated how oneincreased carbon dioxide levels in the atmosphere leads to a rising temperatures on the Earth’s surface.

In the 1960s, he led the development of physical models of Earth’s climate and was the first to explore the interaction between the radiative balance and the vertical transport of air masses. His work laid the foundations for the development of current climate models.

German Hasselmann, 89, created ten years later a model that links weather and climate, thus answering the question of why climate models can be reliable despite the changing and chaotic weather.

Also methods developed to identify specific signals, like fingerprints, which natural phenomena and human activities imprint on the climate.

Their methods have been used to show that the increase in temperature in the atmosphere is due to human emissions of carbon dioxide.

Parisi’s contribution

Around 1980, the Italian Parisi, 73 years old, discovered patterns hidden in complex messy materials.

His discoveries are among the most important contributions to the theory of complex systems.

They allow us to understand and describe many materials and phenomena that seem totally random, not only in physics but also in other very different fields, such as mathematics, biology, neuroscience and machine learning.

Nobel Prizes

The Physics Prize announcement follows that of Medicine yesterday, which was awarded to molecular biologists David Julius and Ardem Patapoutian for their discoveries on temperature and touch receptors, and those of Chemistry and Literature. will be known in the coming days of Peace and Economy.