Crafoord Prize Laureate showed that many factors affect the climate

Carbon dioxide emissions are not solely responsible for climate change. Other substances and small particles, like aerosols, also have an impact on the climate. One researcher who has made valuable contributions that show how this complex system is interconnected is Veerabhadran Ramanathan, University of California San Diego, USA.

“He has expanded our view of how humankind is affecting the atmosphere’s composition, the climate and air quality, and how these three interact,” says Ilona Riipinen, professor of atmospheric sciences at Stockholm University and member of the Crafoord Prize Committee for Geosciences.

Already in the 1980s

As early as the 1980s, professor Ramanathan played an important role in NASA’s use of satellites to measure Earth’s energy budget – the balance between energy from the Sun that reaches Earth in the form of radiation and the heat that Earth then emits back into space. The results showed that greenhouse gases from human activities are trapping an increasing proportion of the re-radiation in the atmosphere and thus contributing to global warming.

Ramanathan also studied how CFCs, known as freons from refrigerators and spray cans, not only affected the ozone layer, but the climate as well. He continued to take an interest in various forms of aerosols, tiny particles, in the atmosphere.

In a large experiment in the Indian Ocean, researchers observed that the air contained high levels of pollutants – even far out at sea. Some of these dark aerosols, such as soot particles, absorb radiation and can thus contribute to heating the atmosphere.

Practical significance

This new knowledge has had great practical significance and formed the basis for international agreements. Ramanathan has influenced many people, from politicians to popes.

“His quiet but effective way of communicating has been key to involving both the research community and decision-makers. With an eye for the most vulnerable on our planet and an ear for younger researchers, he has inspired an entire generation of climate scientists,” says Örjan Gustafsson, professor of biogeochemistry at Stockholm University.

Based on fundamental principles

Professor Ramanathan himself is delighted and honoured on learning that he has been awarded the Crafoord Prize. Among other things, he highlights how important it is that climate research, which has recently become a matter of debate, is being rewarded by the Royal Swedish Academy of Sciences.

“This prize shows that climate science is based on the best possible observations and fundamental principles of physics and chemistry. It gives me a forum to talk about the science of climate change and build public trust in climate science.”