Executive Board visits Institute of Environmental Sciences: ‘Optimism-led solutions’
The Executive Board is visiting the university’s institutes to find out what is going on. On 8 July 2025, it was the turn of the Institute of Environmental Sciences (CML), one of the fastest-growing institutes at Leiden University. ‘Our main aim is to preserve our planet for future generations.’
The CML started out in the 1970s as an ‘activist institute’, says scientific director Martina Vijver, when campaigning scientists came together to oppose a new motorway through the dunes. Now a fully-fledged university institute, the CML has 305 staff members (160 FTE), two master’s programmes, a brand-new bachelor’s programme and various minors. It has grown significantly in the past 10 years, with an influx of young talent: 75 per cent of the staff are younger than 40.
Social engagement
The CML still has a strong sense of social engagement and collaborates with many other disciplines. Its research and teaching focus on how to maximise our well-being within our planetary boundaries. The institute is organised around five sustainability themes headed by lecturers: cities, food, water, biodiversity and natural resources and energy. ‘We deliberately chose these to give our environmental research a focus. The research tools and approaches we use within our research on these themes set us apart from universities,’ says Vijver.
Living labs and solution-focused research
The researchers mainly use quantitative tools, using various data collection methods such as modelling and experimental and field measurements. One example is the use of living labs to conduct solution-focused research into concrete societal problems. ‘This transforms environmental sciences from confronting negative challenges to creating optimistic solutions,’ says Vijver. Research is conducted in the Polder Lab, for example, into the complex interactions between land use (agriculture in particular) and water management.
Knowledge safari
After an introduction by Vijver, René Kleijn (Professor of Industrial Ecology) and Stefano Cucurachi (Director of Education), the Board were taken on a knowledge safari through the offices of a dozen researchers. Each researcher gave a short pitch about their research.
Tomer Fishman (associate professor) spoke about his research on global emissions from concrete, steel and asphalt production. He conducts research on social media, for instance, which gives him a picture of what materials are used in construction. Rugter Hoekstra (associate professor) explained how he is trying to measure ‘broad prosperity’. How do you measure happiness, quality of living environment and social equality as an alternative to GDP? And Valerio Barbarossa (assistant professor) spoke about his research on how mining impacts biodiversity. Many metals are needed for sustainability, but what are the environmental costs of mining them? This also relates to the research by Robert Istrate (assistant professor), who is mapping out the raw materials needed for the solar panels, batteries and data centres used in the energy transition.
Future plans
The Executive Board was clearly impressed with how varied and socially relevant the research is. ‘There was a lot of information to take in,’ said Vice-President Timo Kos. ‘But it was great to meet the researchers in person and to see the projects our people are working on.’
After the knowledge safari, the Board spoke with the institute leaders about its plans for the future. ‘What are your ambitions and how much do you plan to grow?’ asked President of the Executive Board Annetje Ottow. Vijver explained that the CML connects its growth and number of staff to the amount of teaching the institute provides. The CML wants to chart a strategic course with controlled growth that centres research, teaching and collaboration with society, with a group-focused organisational structure and an interdisciplinary approach.