STOCKHOLM: Portraits of the co-winners of the 2021 Nobel Prize in Physics (from left) Syukuro Manabe, Klaus Hasselmann and Giorgio Parisi are displayed on a screen at the Royal Swedish Academy of Sciences in Stockholm yesterday. - AFP

STOCKHOLM: US-Japanese scientist Syukuro Manabe, Klaus Hasselmann of Germany and Giorgio Parisi of Italy yesterday won the Nobel Physics Prize for climate models and the understanding of physical systems, the jury said. The Nobel committee said it was sending a message with its prize announcement just weeks before the COP26 climate summit in Glasgow, as the rate of global warming sets off alarm bells around the world.

"The world leaders that haven't got the message yet, I'm not sure they will get it because we are saying it. But... what we are saying is that the modelling of climate is solidly based in physics theory," said Thor Hans Hansson, chair of the Nobel Committee for Physics. Manabe, 90, and Hasselmann, 89, will share half of the 10 million kronor ($1.1 million) prize for their research on climate models, while Parisi, 73, won the other half for his work on the interplay of disorder and fluctuations in physical systems.

"Syukuro Manabe and Klaus Hasselmann laid the foundation of our knowledge of the Earth's climate and how humanity influences it," the Nobel Committee said. "Giorgio Parisi is rewarded for his revolutionary contributions to the theory of disordered materials and random processes," it added. "The discoveries being recognized this year demonstrate that our knowledge about the climate rests on a solid scientific foundation, based on a rigorous analysis of observations," Hansson said.

Manabe is affiliated with Princeton University in the US, while Hasselmann is a professor at the Max Planck Institute for Meteorology in Hamburg. Parisi, who also won the prestigious Wolf Prize in February, is a professor at Rome's Sapienza University. Working in the 1960s, Manabe showed how levels of carbon dioxide in the atmosphere correspond to increased Earth surface temperatures. He was influential in developing the physical models of Earth's climate and explored how the heat received by Earth from the Sun radiates back into the atmosphere.

Hasselmann was credited for working out how climate models can remain reliable despite sometimes chaotic variation in weather trends. The Committee praised his identification of climate "fingerprints" caused by both natural and human activities and how much climate change can be attributed solely to manmade emissions. Already three decades ago, Hasselmann issued an eerily accurate warning about where the climate was headed.

"In 30 to 100 years, depending on how much fossil fuel we consume, we will face a very significant climate change," Hasselmann said in a 1988 interview, according to a statement from the Max Planck Society in Germany. Speaking to the Nobel Foundation after the award was announced, Hasselmann stressed the need for urgent action. "There are many things we can do to prevent climate change," he said, adding that he thought the issue depended on "whether people will realise that something which will happen in 20 or 30 years is something you have to respond to now."

Parisi was honored for his work in the 1980s that was said by the Committee to be "among the most important contributions" to the theory of complex systems. His work helped physicists understand apparently entirely random materials, with wide-ranging applications including mathematics, biology and machine learning.

Linking Manabe and Hasselman's work to Parisi's, the Nobel Foundation said this year's prize "recognizes new methods for describing complex systems and predicting their long-term behavior". "One complex system of vital importance to humankind is Earth's climate." "I think the award is important not only for me but also for the other two because climate change is a huge threat to humanity and it is extremely important that governments act resolutely as quickly as possible," Parisi told a press conference at the Lincean Academy in Rome.

In Geneva, the head of the World Meteorological Organization, Petteri Taalas, said the prize demonstrates that "climate science is highly valued, and it should be highly valued". Yesterday's award was the first Nobel in physics to honor climate work but the subject has previously received the Nobel nod in other disciplines. The UN's IPCC, which received the Peace Prize together with former US vice president Al Gore in 2007, welcomed the award and congratulated the laureates in a statement.

"It is encouraging to see the Nobel Physics Prize recognizing the work of scientists who have contributed so much to our understanding of climate change," said Hoesung Lee, chair of the Intergovernmental Panel for Climate Change. He noted that both Manabe and Hasselmann had contributed to the IPCC's assessment reports in the 1990s. Manabe told Japanese broadcaster NHK he was "honored" and "surprised" to receive the prize, adding: "The world suffers from drought and wildfire. Maybe (the award) has something to do with these." - AFP