“We are at the start of a new climate regime”

Swiss scientist Sonia Seneviratne is one of the most influential climate scientists in the world. An expert in extreme weather events – such as the exceptional heatwave that recently hit Canada and the United States – she says solutions exist if we are prepared to change our habits.

This content was published on August 9, 2021 – 10:00

August 9, 2021 – 10:00

Luigi Jorio

“I was going into space,” explains Sonia Seneviratne in an interview with SWI swissinfo.ch. “I was fascinated by the planets, the universe, and I wanted to study astronomy. But then I thought to myself that there was something more urgent here on Earth.

So began Seneviratne’s career in environmental and climate sciences. Now a professor at the Swiss Federal Institute of Technology in Zurich, she is at the forefront of climate research, trying to understand the causes of extreme weather events such as heat waves, floods and droughts.

Heat waves 150 times more likely

Her most important finding is the existence of a direct link between extreme events and global temperatures, she explains, as well as the fundamental role of vegetation in keeping carbon levels low. This is a link that was first pointed out in a groundbreaking report on the impacts of global warming of 1.5 ° C, published in 2018 by the Intergovernmental Panel on Climate Change (IPCC) of United Nations.

The Zurich researcher also looked into the causes of the exceptional heatwave that hit North America in June. Due to climate change, she says the probability of such events has increased 150-fold. In other words, prolonged periods with temperatures close to 50 ° C could occur every five to ten years, instead of ‘once a millennium.

Through satellite measurements and field observations, Seneviratne also discovered that droughts have an impact on the amount of CO2 in the atmosphere, a phenomenon previously underestimated by climate models. During dry periods with high temperatures, plants absorb less CO2, which contributes to further warming of the air, she explains.

Thanks to this work and numerous scientific articles, Seneviratne was included in the list of the 1,000 most influential climate scientists in the world, compiled by the global news agency Reuters. Ranked ninth, she is the only woman in the top 30.

“I wanted to learn the dictionary by heart”

As a child, Seneviratne was curious about the world around her and loved to walk in the woods and observe the trees. In her spare time, she read a book or two a day. She also wrote short stories. “I wanted to learn everything, even the whole dictionary by heart. “

It was during the Rio Earth Summit in 1992 that she first became aware of environmental problems and climate change, recalls the 47-year-old.

Once enrolled in a biology course at the University of Lausanne, she never missed a course in mathematics or physics, her favorite subjects. “But I also have bad memories of working in the lab. I used to break everything, ”she recalls with amusement. In the third year of her studies, she transferred to ETH Zurich, at the time among the few European universities to offer an interdisciplinary program in environmental sciences.

While there, Seneviratne gained knowledge about the effects of vegetation on climate through his masters work in the Amazon rainforest and through a postdoctoral fellowship at NASA.

During an academic exchange at the Massachusetts Institute of Technology, she met several other women who wanted to become professors in a field traditionally dominated by men. “The biggest difficulty in Switzerland was the lack of female role models, which I had met in the United States. They opened up new horizons for me, ”she says. Back in Switzerland, she was appointed professor when she was only 32 years old.

“One of the best researchers in Switzerland”

Modest by nature, Seneviratne “always manages to identify the major questions in our field and helps to solve them”, explains Wim Thiery, climatologist at the Vrije Universiteit Brussel, who carried out his post-doctoral research in his laboratory, quoted by the newspaper . The weather.

In another French-speaking daily, 24 hours, climatologist from the University of Neuchâtel, Martine Rebetez, describes her as “one of the best researchers in Switzerland. The first time I met her I was like, ‘Wow! Here is someone who is pretty bright and doesn’t realize it. Besides, he’s a really nice person ‘”.

Stop using fossil fuels

“Climate change is now,” warns Seneviratne, who does not hide his frustration at the lack of decisive action on climate protection. “We are at the start of a new climate regime, but not everyone realizes it.”

Switzerland is more or less prepared, she believes, but has not sufficiently understood that the effects elsewhere in the world will also be felt here. “We import half of our food from abroad. What will happen in the future if the agricultural regions of the world are simultaneously struck by drought and decide, for example, to suspend exports to meet domestic needs?

The researcher calls for mobilization at all levels. The solution, she says, is very simple: “We must stop consuming fossil fuels. The alternatives are there, although a lot of people are afraid of change, ”she said. “We don’t need to fundamentally change our lifestyles. We can continue to lead an equally comfortable life while producing fewer emissions. “

Climate action in court

As a citizen, Seneviratne tries to reduce her own impact by reducing her meat consumption, avoiding the car and preferring the train to the plane to travel in Europe.

As a researcher, she is happy to present to the courts the current state of knowledge in her field, as she did in January during a lawsuit against climate activists who had occupied a branch of Bank Credit. Switzerland in Lausanne. “Judges think more in the long term than politicians. I believe that the courts can play an important role in the fight against climate change, as some decisions in Germany and France show, ”she said.

After the Lausanne trial, the judge said it was the “depth and precision” of Seneviratne’s statements that convinced the court to acquit the defendants at first instance. The climate activists were then sentenced on appeal. While acknowledging the imminent climate danger, the cantonal court ruled that the protest action “was not suitable to reduce or curb” greenhouse gas emissions.

Sleepless nights writing reports

Seneviratne also contributes to international climate reports. For the latest IPCC assessment report, the first part of which was published on August 9, she coordinated the chapter on extreme events. This unpaid activity is added to his daily work and often spills over into the evenings and weekends.

“As a researcher, I find it an interesting task because it gives me the chance to read hundreds of studies and see where the gaps lie. But, most of all, I’m doing it because I feel like I’m doing something useful to help deal with the climate emergency.

“But, given the many sleepless nights,” she said with a smile, “I’m not sure if I will participate next time.”