Three scientists have been awarded the 2021 Nobel Prize in Physics for their work to understand complex systems such as the Earth’s climate.
Syukuro Manabe, Klaus Hasselmann and Giorgio Parisi were announced as the winners at an event in Stockholm.
The work by Manabe and Hasselmann led to computer models of the Earth’s climate that could predict how global warming would change the environment.
The winners will share the prize money of 10 million krona (£842,611).
It is very difficult to predict the long-term behaviour of complex physical systems such as our planet’s climate. But computer models that can anticipate the effects associated with emissions from burning fossil fuels have been crucial to our understanding of climate change.
Syukuro Manabe demonstrated how increased levels of carbon dioxide in the atmosphere could lead to increased temperatures at the surface of the Earth. In the 1960s, he led the development of physical models of the climate.
Roughly a decade later, Klaus Hasselmann created a computer model that linked together weather and climate. His work answered the question of why climate models can be reliable despite weather being changeable and chaotic.
The committee said Giorgio Parisi’s discoveries made it “possible to understand and describe many different and apparently entirely random materials and phenomena”. This included the behaviour of complex systems at the microscopic level.
His work has applications not only in physics but also in other, very different areas, such as mathematics, biology, neuroscience and machine learning (an area of artificial intelligence).
Asked about the timing of the climate-themed award, with the UN’s climate conference in Glasgow just weeks away, Prof Parisi said: “We have to act now in a very fast way and not with a strong delay.”
The Swedish industrialist Alfred Nobel founded the prizes in his will, written a year before his death in 1896.
A total of 218 individuals have now won the physics prize since it was first awarded in 1901.
Only four of these laureates have been women. One physicist, John Bardeen, won the prize twice – in 1956 and 1972.