Nobel Prize in Physics, 2021, awarded for work in climate change and understanding complex systems

The Nobel Prize in physics for the year 2021 for ground-breaking contributions in helping us understand and predict complex forces of nature and also for explaining the disorder in physical systems ranging from the atomic to the planetary scale.

One half of the award was jointly given to Syukuro Manabe, a Japanese educated American climatologist, for ground-breaking contribution to the understanding of the complex physical systems on Earth and Klaus Hasselmann, a German oceanographer, for reliably predicting global warming. The other half was awarded to Giorgio Parisi, an Italian theoretical physicist, for explaining the disorder in physical systems ranging from the atomic to the planetary scale. All three scientists’ work is focused on what is known as complex systems, i.e., a system that is difficult to model due to its various components interacting with each other. Earth’s climate is a complex system among others like organisms, the human brain and so on.

Syukuro Manabe, 90, is a professor at Princeton University. He is a well-known climatologist who started his work in the 1960s. He received the 2021 Nobel Prize for his revolutionary contributions to our understanding of complex physical systems. The research he did and the papers he published in the 1960s are some of the most iconic and influential papers and research on the climate of the Earth ever. His work on predictions of climatic conditions on Earth is by far the best research anyone has ever done on complex physical systems of which Earth’s climate is an example. In 1967 he published a paper where he built a climate model that showed that the temperature of the Earth’s surface and the troposphere increased on increase in the carbon dioxide content in the atmosphere. This paper was so influential that climatologists call it the “most influential climate paper ever”. Manabe’s models from 50 years ago were accurate predictions of global warming that occurred in the subsequent decades. His subsequent papers and research have made an impact for every climate scientist that has followed.

Klaus Hasselmann, 90, is professor Emeritus at the University of Hamburg and is the former director of the Max Plank Institute of Meteorology. He received the 2021 Nobel Prize for his work in creating models for Earth’s climate, quantifying climatic variability (mathematically explaining climatic changes) and for accurately predicting global warming.His research is focused mainly in the field of oceanography but his work in climate dynamics is no less. In the field of climate change he has given a mathematical explanation of how the climate change can be brought about by the randomly changing weather patterns. He has helped explain why climate models are reliable despite the seemingly random and chaotic patterns of weather. He has also developed ways to look for specific signs of anthropogenic climate change, i.e., climate change brought about by the actions of human beings. He is best known for developing the Hasselmann Model of climatic variability that focus mainly on oceans.

Giorgio Parisi, 73, is a professor of quantum physics at the Sapienza University in Rome. His research is focused on quantum field theory, statistical mechanics and complex systems. He received the 2021 Nobel Prize for explaining the interplay between the disorder and quantum fluctuations observed in complex systems at scales ranging from the atomic to the planetary. His best known contributions are the Altarelli-Parisi equations in quantum chromodynamics, the exact solution of the Sherrington-Kirkpatrick model of spin glasses, the Kardar-Parisi-Zhang equation and the study of whirling flock of birds. His work is some of the most iconic work in the field of quantum field theory and statistical mechanics.

After receiving the prize, the three scientists made use of their opportunity in the spotlight to talk about why climate change is a major concern and something should be done about it. In particular Hasselmann said that he would be satisfied with not having the Nobel Prize if global warming wasn’t a major concern. Manabe said that figuring out the physics behind climate change was a 1000 times easier than actually getting the world to do something about it and that the complexities and intricacies of society and public policy are far harder to fathom than the connection between the temperature of the Earth’s surface and the concentration of carbon dioxide in the atmosphere. He, like many other, called climate change a major concern. Even though, Giorgio Parisi won the award for work in a different field, he used this opportunity to make his concerns about the threat of global warming and the need to do something about it clear to the world.

Nobel Prize winners receive 10 million Swedish Kroner and a medal as their award. Manabe and Hasselmann shared one-fourth of the cash prize each while Parisi received half of the cash prize.