Each year a staggering 18 billion chickens, turkeys, pigs, sheep, goats, and cows either die or are killed without making it onto someone's plate. Environmental scientists Juliane Klaura, Laura Scherer, and Gerard Breeman were the first to calculate this number on a global scale. 'Reducing these numbers…

Many students are finishing their master thesis on sustainability this summer. In this blog, we reflect on their topics, approaches, and goals by highlighting theses from Governance of Sustainability, European Law, Global Archaeology, Computer Science: Artificial Intelligence, Industrial Ecology, and…

Do you want to find solutions to environmental problems that make a real impact? Do you have a broad interest and want to learn from insights from the natural and social sciences when analysing complex sustainability challenges? Then Science for Sustainable Societies at Leiden University may be the…

This book offers a linguistic anthropological analysis of multilingualism among the Matsigenka, Quechua, and Spanish languages on the coffee frontier of Southern Peru, set against the backdrop of economic transformation and deforestation in the world’s last great forest.

World history, connectivity and material culture, edited by Martin Pitts and Miguel John Versluys. From Cambridge University Press.

The research that is united in the Liveable Planet programme, touches upon a wide range of aspects of human life. The goal is to deepen and expand the scope and to connect more researchers. The following case studies are examples of current research projects.

During the bachelor’s programme Astronomy you will immerse yourself in questions about our universe. Questions such as: ‘what happens in a black hole?’ and ‘what is dark matter?’ In doing so you will learn to apply mathematics and physics to astronomical problems and you will work with computer simulations…

Soil is a home for an unbelievable diversity and abundance of microbial life that is essential for supporting life on our planet.

The Old Observatory is still used intensively as a university building. Yet there is still plenty to see and experience in this beautiful monument. Find out what the possibilities are here.

Research into the evolutionary backgrounds of our diets can help us make the right choices in diet, health and lifestyle.

This thesis aims to demonstrate how the achromatic nature and design flexibility of liquid-crystal optics can be used to improve high-contrast imaging instruments to facilitate detailed exoplanet characterization.

Our current lifestyle is not sustainable, and we know it. Our carbon-based economy causes climate change, and our livestock threatens the rainforests. We also know what we ought to do to save the planet: decarbonize the economy and change our diet. However, too many people lack the moral motivation…

The zoo of detected exoplanets reveals both the uniqueness of our own Solar System and the complexity of planetary system formation, sparking fundamental questions about how planetary systems form and evolve.

An international team of astronomers including Leiden scientists publishes the image of a young star with a surrounding dust disk that is still being fed from its surroundings. The phenomenon around the star SU Aur may explain why so many exoplanets are not neatly aligned with their star. The European…

‘The climate crisis is the greatest threat we face,’ says Leiden University environmental scientist Paul Behrens. ‘And yet, there is hope. In the near future, I think we will wonder why we didn’t make these changes earlier.’

How dangerous are micro- and nanoplastics? Do they affect the environment? What harm can they do to our bodies? Questions that we can now finally answer because of Fazel Abdolahpur Monikh. Together with his colleagues, he developed a method to detect and quantify nano-sized plastics. Their paper has…

Sustainability challenges don’t just call for environmental scientists – they require expertise from many academic fields. Thijs Bosker and Paul Behrens have made it easier for university lecturers to integrate sustainability into their courses. Their initiative, Local Actions, offers ready-made teaching…

Nanoplastics influence the behaviour of larval zebrafish, says new research by the Institute of Biology Leiden (IBL) and the Institute of Environmental Sciences (CML). The researchers observed that a certain type of nanoparticles leads to stress reactions in the sugar balance, resulting in hyperactivity…

These podcast episodes were written for the Green Office’s Spring Podcast competition and miniseries 'Beyond the Safe Space', on the theme: the Planetary Boundaries, which took place between the months of March-May 2023.

Is there extra-terrestrial life out there? It now looks as though we can sketch out an answer to this enduring question. Leiden Observatory is helping to build new instruments to find the most promising exoplanets.

We are very excited to announce our Sustainability Series for 2023-2024. Each month an interactive workshop will be organised that discusses a specific theme of sustainability. Interested about sustainability? Do not hesitate to sign up to our events !

Science for Sustainable Societies offers an exciting combination of theory and practice. While analysing and examining relevant topics from both the natural and the social sciences domains, you will also gain lots of hands-on experience. Interactive learning and working together in a team are important…

A lot of municipalities work with a points system to encourage construction projects to take biodiversity and creating green areas into account. But this way of working also benefits local neighbourhoods and residents, master's student Marije Sesink discovered. She based her study on The Hague.

Democracy may lead to more deforestation in the tropics. So write environmental scientist Joeri Morpurgo and his colleagues in the prominent scientific journal Biological conservation. They found that competitive elections are associated with more loss of tropical rainforest than elections without competition.…

The province of Zuid-Holland faces a wide range of global sustainability issues caused by urbanisation, intensive horticulture and industry. The universities of Leiden, Delft and Rotterdam have the in-house expertise to define knowledge questions, set up research programmes and test results, says Prof.…

The availability of natural resources, the energy transition, the importance of circularity and our dependence on China. This and more is what Professor of Industrial Ecology René Kleijn's inaugural lecture is about.

Local residents, scientists and students are investigating riverbanks in Leiden for the 'Bank Plants' citizen science project. Which plant species are found where? And how can the municipality of Leiden improve its riverbank management to ensure optimal biodiversity?

With 8.9 million euros from the Danish National Research Foundation, Aarhus University and Leiden Observatory will establish the Center for Interstellar Catalysis. The centre is led by Aarhus professor Liv Hornekær and aims to find out how and when the building blocks of life formed in the Universe.…

NASA’s telescope SOFIA has provided a new glimpse of the chemistry in the inner region surrounding massive young stars where future planets could begin to form. Leiden PhD candidate Andrew Barr writes about it in the Astrophysical Journal. The scientists found massive quantities of water and organic…

During the Leiden Science Family Day, you can take part in various workshops. You can also watch various demonstrations. Where will you go?

This project studies the roles of prehistoric foragers in past ecosystems to establish the character of past “natural” landscapes and enhance the management of current ones.

We investigate water quality and want to understand the effects of human interference on aquatic biodiversity.

This study aims to provide a long time perspective of human landscape manipulation. Studying the roles of prehistoric foragers in past ecosystems is of great importance to establish the character of past 'natural' landscapes and to enhance the management of current ones.

Cooperation with Latin America aims to build on the long-standing relation that Leiden University has with multiple partners in the region.

On this page, you will find the recordings of the Tuesday Talks since April 2025. Recordings of the precursor to the Tuesday Talks, This Week’s Discoveries, are also available here.

eLaw examines the role of law in the information society: how can law contribute to the proper functioning of information and communication technologies, and their use by citizens, businesses and governments?

Turning scientific insight into real-world impact. With The Krijn Rietveld Memorial Awards, dsm-firmenich honours outstanding researchers - from master's to postdoctoral researchers and start-ups - across life sciences, (environmental) health sciences and biotechnology, with data science at the core…

On 21 January, the Institute of Environmental Sciences (CML) has released two reports on circular economy and urban mining in the Netherlands. In them, together with Statistics Netherlands, they take stock of part of the Dutch ‘urban mine’: how much raw material can we reuse from the electricity grid,…

Do you deeply care about our planet and are you eager to make a real change? Then our two-year MSc programme Industrial Ecology may be the place for you. The interdisciplinary programme, offered jointly by Leiden University and TU Delft, is a true powerhouse for sustainability solutions. As a student…

The ‘Schijf van Vijf’ is the Dutch official dietary guideline, similar to a food pyramid, that shows what a healthy daily diet looks like. The updated version places more emphasis on plant-based eating. But how big is the impact of that shift really? We asked environmental scientist Joran Lammers.

How can we best deal with the current problems caused by the human impact on the nitrogen cycle? How do we make the transition to a sustainable society? As of 1 September, nitrogen expert Jan Willem Erisman will be working on these questions at Leiden University: he will exchange the Louis Bolk Institute…

An international team led by Leiden astronomers has, after years of searching and defying the boundaries of a telescope, for the first time directly captured polarised light from an exoplanet. From this light they can deduct that a disk of dust and gas orbits the exoplanet. In this disk moons are possibly…

Researchers using NASA’s James Webb Space Telescope may have detected atmospheric gases surrounding 55 Cancri e, a hot rocky exoplanet 41 light-years from Earth. This is the best evidence to date for the existence of any rocky planet atmosphere outside our solar system.

A group of astronomers led by Leiden PhD student Sebastian Zieba has discovered using the James Webb Space Telescope (JWST) that the rocky exoplanet TRAPPIST-1 c has a thin atmosphere. Although the planet is nearly identical to Venus in size and temperature, and was expected to have a thick atmosphere,…

An international team of astronomers have become the first in the world to detect isotopes in the atmosphere of an exoplanet. It concerns different forms of carbon in the gaseous giant planet TYC 8998-760-1 b. The research will be published in the scientific journal Nature on Thursday.

Astronomers at Leiden University have discovered the first planets using a new instrument: the planet hunter MASCARA. This instrument, developed at Leiden Observatory, looks specifically for planet transitions around the brightest stars in the sky, which surprisingly enough have so far have hardly been…

All the planets in our solar system orbit around the Sun in an ecliptical plane. This is to be expected because our solar system was formed from a so-called protoplanetary disc. PhD candidate Anna Miotello has studied these kinds of discs and how they influence the formation of stars and planets. PhD…