The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Physics in 2021 “for groundbreaking contributions to our understanding of complex physical systems,” with half going to Syukuro Manabe and Klaus Hasselmann “for physical modelling of Earth's climate, quantifying variability, and reliably predicting global warming,” and the other half going to Giorgio Parisi “for the discovery of new methods for predicting global warming.”
The Nobel Prize in Physics is shared by the three laureates this year for their research into chaotic and seemingly random occurrences. Syukuro Manabe and Klaus Hasselmann laid the groundwork for our understanding of the Earth's climate and its impact on humans. Giorgio Parisi is honored for his groundbreaking contributions to disordered materials and random processes theory.
Complex systems are difficult to comprehend since they are characterized by randomness and disorder. This year's prize honors novel approaches to defining and forecasting their long-term behavior.
The Earth's climate is a complex system that is critical to humanity. Increased quantities of carbon dioxide in the atmosphere lead to higher temperatures at the Earth's surface, according to Syukuro Manabe. He was the first to investigate the interplay between radiation balance and vertical air mass movement in the 1960s, and he spearheaded the development of physical models of the Earth's climate. His work set the groundwork for the current generation of climate models.
Klaus Hasselmann constructed a model that relates weather and climate ten years later, answering the question of how climate models can be trustworthy despite the fact that weather is unpredictable and chaotic. He also devised ways for recognizing precise indications, or fingerprints, that both natural and human-caused climate change leave behind. His methods have been used to demonstrate that the increased temperature in the atmosphere is caused by human carbon dioxide emissions.
Giorgio Parisi identified hidden patterns in chaotic complex materials in the early 1980s. His contributions to the theory of complex systems are among the most significant. They enable us to comprehend and characterize a wide range of seemingly random materials and occurrences, not only in physics but also in fields as diverse as mathematics, biology, neuroscience, and machine learning.
“This year's results show that our understanding of the climate is founded on a strong scientific foundation, based on a rigorous study of observations. Thors Hans Hansson, chair of the Nobel Committee for Physics, states, "This year's laureates have all contributed to our obtaining deeper knowledge into the properties and evolution of complex physical systems."