Climate scientists Klaus Hasselmann and Syukuro Manabe win Nobel Prize in Physics

Scientists helped prove human activity is causing climate change

The winners of the 2021 Nobel Prize in Physics are displayed on a screen in Stockholm, Sweden. Photo: AFP

Two scientists who helped to prove that human activity is spurring climate change have won the Nobel Prize in Physics.

Klaus Hasselmann, 89, and Syukuro Manabe, 90, were honoured for “laying the foundation of our knowledge of the Earth’s climate”, the jury said.

They shared the award with Giorgio Parisi, from Italy, who shed light on a variety of complex systems including atoms and ice ages.

“The discoveries being recognised this year demonstrate that our knowledge about the climate rests on a solid scientific foundation,” said Thors Hans Hansson, chairman of the Nobel Committee for Physics.

“This year’s laureates have all contributed to us gaining deeper insight into the properties and evolution of complex physical systems.”

Dr Manabe is a Japan-born US citizen affiliated to Princeton University. Dr Hasselmann is from Germany and worked at the University of Hamburg.

The Nobel jury said Dr Manabe’s work, stretching back to the 1960s, had shown that an increase in carbon dioxide in the atmosphere was contributing to climate change.

His work laid the foundation for the development of current climate models, the Royal Swedish Academy of Sciences said.

Dr Hasselmann worked on methods to detect humanity’s impact on the climate, which paved the way for proof that greenhouse gas emissions are affecting the planet.

He created models that linked weather and climate, showing that scientists could make reliable long-term climate forecasts despite the volatile nature of day-to-day weather.

The two climate scientists will each take a quarter of the Nobel winnings. Dr Parisi, 73, will take half. The total prize is 10 million Swedish crowns ($1.1m).

Dr Parisi made discoveries about “how apparently random phenomena are governed by hidden rules”, the Nobel committee said.

His theories helped to explain a wide range of phenomena, not only in physics but also mathematics, biology, neuroscience and machine learning.

The awards show how scientists can sometimes win Nobel Prizes many years after their discoveries. Nobel organisers say it can take time for a breakthrough to be fully appreciated and understood.

Climate change has increasingly come to the foreground in recent years as natural disasters and dire warnings about the future prompt calls for political action.

Nobel committee members speak to the media after the winners of the physics prize were announced. Photo: AFP

The physics prize was the second to be handed out in this year’s Nobel awards season.

On Monday, two biologists who studied the human senses won the prize in physiology or medicine.

The Swedish science academy had honoured astronomy breakthroughs in the past two years, leading to speculation that a change of field was due.

Winners of the chemistry, literature, peace and economics awards will announced this week.

The physics award was first presented in 1901. Previous winners include Albert Einstein and Pierre and Marie Curie.