By Kenneth Evans, Ph.D.
Scholar in Science and Technology Policy
This year’s Nobel Prize in Physics was awarded to three scientists for their contributions to our understanding of the chaos — both natural and human-made — that underlies, and helps us predict, global climate change. Klaus Hasselmann (Max Planck Institute for Meteorology), Syukuro Manabe (Princeton University) and Giorgio Parisi (Sapienza University of Rome) shared the award for their “groundbreaking contributions to our understanding of complex systems,” including the Earth’s climate. This announcement is the first occasion that the physics prize has recognized climate science, a welcome shift in Nobel’s 120-year history, demonstrating the reach of mathematical and computational physics beyond its traditional boundaries in addressing global challenges.
Half of this year’s prize was awarded to Parisi, an Italian theoretical physicist, “for the discovery of the interplay of disorder and fluctuations in physical systems from atomic to planetary scales.” Parisi was recognized for his foundational research in the 1970s and 1980s on “spin glasses,” a class of metal alloys that display exotic magnetic properties caused by disorder in their atomic structure. The complex structures contained in spin glasses that Parisi described have proved to be of wide, interdisciplinary utility, and have since been applied toward understanding many disordered systems found in nature, such as neural networks, patterns of flocking birds and the focus of this year’s prize — climate science.
The other half of the physics prize was shared by Manabe, a Japanese American climatologist, and Hasselmann, a German oceanographer, “for the physical modeling of Earth’s climate, quantifying variability and reliably predicting global warming.” In the 1960s, Manabe pioneered the use of computer simulations in climate science, developing the first climate model that uncovered the relationship between increased CO2 in the atmosphere and increases in Earth’s surface temperature. Over the next three decades, Manabe led the development of increasingly complex climate simulations that incorporated the global circulation of air and water, laying the foundation for our current models estimating the future of global warming. Hasselmann, in the 1970s, similarly contributed to modern climate simulations, producing the first such model that could reliably predict long-term climate change due to short-term fluctuations in weather, as well as human activities such as pollution.
Critics of the Nobel Prize have long advocated for the Nobel science awards to expand beyond the three established disciplines —medicine, physics and chemistry — to be more inclusive of other fields not easily categorized by the Nobel’s outdated classifications. This year’s physics prize takes a step in the right direction, recognizing a physical science outside of the Nobel’s traditional wheelhouse; just as recent examples, the science Nobels in 2020 went to astrophysics, in 2019 to planetary science and in 2018 to laser physics. “I am so surprised,” Manabe said about his award. “Nobody has received the physics prize for my kind of work, and I really appreciate the Swedish Academy of Sciences [for choosing] this field, climate topics and climate change.”
The Nobel committee’s choice to broaden the scope of its awards, which has historically been conservative in its interpretation of what counts as “physics,” to include climate science is a welcome — and much needed — change in the long history of the physics prize. And while one year does not indicate any systemic change to the Nobel’s awarding procedures, this year’s award is demonstrative of what the world’s most visible scientific prize can deliver if it continues to grow to reflect and reward how science is conducted today, rather than how science was defined and performed in 1901. It is no coincidence the 2021 United Nations Climate Change Conference begins in just several weeks. The Nobel committee did well to highlight the research of Hasselmann, Manabe and Parisi, and to recognize climate science as a part of the physics cannon, in advance of this crucial meeting of nations to reaffirm a global commitment to combating climate change.