Julian Rogger shows how plants regulate the climate

Astrid Tomczak-Plewka

"I am privileged to have always been able to pursue my interests." The young man saying this had varied interests even as a child – which turned the privilege into a challenge. Originally Julian Rogger wanted to be a professional musician, played bass and guitar in a band, and completed his foundation course at the Lucerne School of Music. Then he decided to pursue other interests – specifically natural sciences and social issues. He sought answers in agricultural science. "It's a matter of utilising the environment whilst simultaneously protecting it. Society, the economy and politics play just as big a role as scientific processes," says the young man from Obwald. His studies started with the major systemic subjects; later he focussed on climate issues and vegetation.

When does the balance tip?

In his thesis for the Department of Earth and Planetary Sciences, he investigated how closely the plant world and climate are interwoven and what happens when this interaction is no longer in balance. In his words: "What are the critical interactions between land, ocean, vegetation and geological processes that regulate the Earth's climate?" In the process, Rogger homed in on the adaptability of plants, as they not only react to changes but also affect them. "When the environment changes, biological systems are also able to adapt to a certain extent," explains Rogger. When the climate changes more quickly than vegetation can adapt, however, they lose part of their climate effect. "Plants absorb less CO2 and warming can also intensify."

Rogger looked deep into the Earth's past to discover where these limits lie. He linked climate and vegetation models with geological data to reconstruct how the climate system has developed over millions of years and when such tipping points might occur in vegetation. This made him "the first to succeed in including geographically specific, adaptable and proliferating plants in carbon cycle models", as his PhD supervisor Taras Gerya wrote. And he stresses that "Julian Rogger is one of the best PhD students that I have ever supervised or co-supervised in term of his intellectual capability, maturity of thinking, scientific independence and quality of his PhD work." You have to be able to cope with so much praise. "These are very impressive words. I feel greatly honoured," says Rogger, "but there are so many PhD students who are producing excellent work and showing great dedication."

He is not only concerned with climate development as a researcher, but also as a human being. "Climate change is a massive societal challenge," he says. "And the clock is ticking." It is even more important to "learn something about the climate system's limits from Earth's geological history". He wants to pursue this path further. "I would love to put together an interdisciplinary research group, and it would be all the nicer if that were to happen in Switzerland," says Rogger. The 31-year-old is currently working as a post-doctoral assistant at the University of Bristol, where he is continuing his research on the reciprocal effects of climate, vegetation and geological processes.

Finding balance in everyday life

Sport helps him maintain a balance with his professional life: when he moved to England, half of the small moving van was filled with his racing bike and his partner’s. "When I’m running or on my bike, I can switch off and clear my head," he says. "It also helps me come up with new ideas and perspectives."

When it comes to music, it is a little different: I think and analyse a lot, "just like in science". It is also worth mentioning that apartments in England are often poorly soundproofed; the rumble of bass frequencies can therefore quickly disturb the neighbours, which is certainly not Julian Rogger’s intention. In fact, in his family he inherited not only an affinity for "fact-based thinking" but also the value of empathy. "If someone has a problem, we first try to understand the situation."

And that is what also motivates Julian Rogger in his research: not merely to observe, but to seek to understand.