Green cities and a well-protected food system: Roy Remme and Oliver Taherzadeh study ways to achieve these. But how can their scientific findings lead to societal change? They share their experiences with science-policy initiatives.
Have you ever wondered how science finds its way from universities to society? Get to know two projects from the Institute of Environmental Sciences (CML) that contribute to science-informed policies.
Oliver, you contributed to a UN report about food security. What did you study?
'I study the relation between diets, food trade, and global environmental change. If you are eating a hamburger in the Netherlands, how does that impact overseas land use, water demand and deforestation? The UN report (see box) is about the impacts of land degradation on food supply and farmer livelihoods. We found that there is a hidden dependency on small farms. They provide 30% of our food. This is concerning given the acute climate risks they face and the lack of climate adaptation support.'
Roy, you developed a handbook to help policy makers make cities greener. Can you tell us more?
'My research is about urban greening strategies. How can we use greenery to improve health and biodiversity, or adapt to climate change? For the handbook, we collected 59 tools that can help city planners and decisionmakers with these questions. One example is a tool that models how greenery can help keep cities cooler or reduce the risk of flooding. You can look at different scenarios to see how different distributions of greenery affect these factors.'
UN Food and Agricultural Organisation - the State of Food and Agriculture report 2025
The UN report is about the role of small-scale farmers in food and resource security within a globalised food system. Taherzadeh, together with CML colleagues Hongyi Cai and Aysegül Çelik, contributed to two large-scale studies. First, an assessment showing that small farms meet diverse food needs of high-income nations. Second, a global analysis illustrating the crucial role small-scale farmers play in global forest protection and success of the EU's deforestation regulation. This work will be further developed within Europe as part of the GreenGrocer project.
Handbook of tools for urban greening
What motivates you to be involved in policy development?
Remme: 'My field is societally relevant. So as a researcher, my work becomes truly relevant once it is used by societal actors. It can be complicated to plan alongside other work, but I believe that this work is not only interesting but also necessary.'
Taherzadeh: 'We can provide solutions to seemingly intractable challenges faced by society. Policy is often the first step to action. But it's also about all of us: we can vote on what food system we want to see three times a day.'
'Invest in communicating to broader audiences in an understandable way.'
What impact do you hope to have?
Taherzadeh: 'The main message of the report is that we need to ensure adequate support for small-scale farmers. We depend on them. But I also hope it makes people realise how food ends up in the supermarket, and that the system behind that is vulnerable.'
Remme: 'Civil servants might not have all the necessary expertise, we can help make our research more accessible. I hope that policy makers will use the handbook to guide them to the most relevant tools for them.'
Do you have tips for colleagues who'd like to follow suit?
Remme: 'Your network is important, so engage in European projects and initiatives. But don't underestimate the time investment. If you want to do this well, you need to invest time.'
Taherzadeh: 'Invest in communicating to broader audiences in an understandable way. Emphasize why your work matters for policy and society. If you affect only one person's choice, you can have impact, and one that will likely be amplified.'
