The Nobel Prize in Physics 2021 - Dr. Syukuro Manabe, Dr. Klaus Hasselmann & Dr. Giorgio Parisi

The Royal Swedish Academy of Sciences has decided to award the 2021 Nobel Prize in Physics, with one half jointly to Dr. Syukuro Manabe and Dr. Klaus Hasselmann “for the physical modelling of Earth’s climate, quantifying variability and reliably predicting global warming” and the other half to Dr. Giorgio Parisi “for the discovery of the interplay of disorder and fluctuations in physical systems from atomic to planetary scale.”

Starting in the 1960s, Manabe, now based at Princeton University in New Jersey, created the first climate models that forecast what would happen to the globe as carbon dioxide built up in the atmosphere. Scientists for decades had shown that carbon dioxide traps heat, but Manabe's work put specifics and prediction into that general knowledge. It allowed scientists to eventually show how climate change will worsen.

About a decade later, Hasselmann, of the Max Planck Institute for Meteorology in Hamburg, Germany, helped explain why climate models can be reliable despite the seemingly chaotic nature of the weather. He also developed ways to look for specific signs of human influence on the climate.

Meanwhile, Parisi, of Sapienza University of Rome, worked on a so-called spin glass, a type of metal alloy in which the atoms are arranged in a way that changes the material's magnetic properties in apparently random ways that baffled scientists. He was able to discover hidden patterns that explained this behavior, theories that could be applied to other fields of research, too.

All three physicists used complex mathematics to explain and predict what seemed like chaotic forces of nature in computer simulations. With the help of modeling, it has given these physicists an accurate understanding of those forces that, for instance, they can accurately predict or warn about the climate decades in advance. Thus, with these work over the past sixty years, they found order in seeming disorder, helping to explain and predict complex forces of nature, including expanding our understanding of climate change.