To achieve this, it must gradually free itself from its dependence on fossil fuels, while at the same time widely expanding renewable energy systems. 

Among these energy sources, solar and wind power hold tremendous potential. 

Their development, however, faces numerous obstacles: the limitations of the electrical grid and connection capacities, issues of social acceptability, and the land required for their installation, which creates conflicts with other land uses.

Understanding the obstacles to the development of renewable energy

These are precisely the issues addressed by the team of the European research project (ERC) Luiret, led by Professor and researcher Eric Lambin. The project focuses on land use and its impacts in relation to the ongoing energy transition.

The European Union is urging its Member States toward a rapid energy transition in order to meet the ambitious targets it has set. 

On the ground, the situation is not so simple, as there are significant spatial constraints, including: (1) conflicts with other land uses; (2) public opposition that may become more or less pronounced; and (3) landscape impacts.

The Luiret project team studies how the various stakeholders (citizens, landowners, developers, administrative authorities, farmers, etc.) make decisions regarding land use and seeks to understand their territorial, social, and environmental impacts.

A lack of territorial justice

Within the team, doctoral researcher Caroline Bottu is particularly interested in the development of solar energy in the mountainous massif of the French Alps. She studies territorial dynamics, regulations, and land-use changes.

The researcher has just published a scientific article, “Mismatch between where solar projects are proposed and approved: the case of PV acceptance in the French Alps”, whose conclusions highlight a lack of spatial justice in the development of solar energy infrastructure.

Caroline Bottu has demonstrated that the majority of photovoltaic parks recently built were concentrated in very few areas. These territories benefit from a higher permit approval rate, which encourages developers to submit more projects there. This mechanism reinforces the concentration of installations.

As a result, more than 50% of solar park projects submitted since 2020 have been located in a portion that represents only 9% of the territory of the French Alps. Populations living in these areas are therefore more likely to see forested or agricultural land disappear, replaced by solar parks.

The views of local residents rarely taken into account

Caroline Bottu’s research shows that residents’ opinions are generally given little, if any, consideration in the final decision by authorities to grant or refuse the permit for a solar park.

The researcher highlights a lack of transparency in the criteria considered by authorities to approve or reject projects. Neither the socio-demographic characteristics of the territories nor the conclusions of environmental impact assessments make it possible to predict the final decision.

The only significant predictor is how transformed the environment already is: the more urbanized or human‑modified a site is, the more likely it is to receive a permit.

Policy recommendations and next steps for the project

Caroline Bottu and the Luiret project team therefore recommend better planning of solar‑park sitting at the local and regional level. 

They call on authorities to demonstrate greater transparency when issuing their decisions. Finally, they suggest taking into account the full range of social, territorial, and environmental impacts when determining the location of a new solar park.

For the remainder of her PhD, Caroline Bottu will focus on citizen energy communities: how do they emerge, and what obstacles do they encounter?

Interested in learning more about the Luiret project? Visit its website.

Caroline Bottu will also give a seminar on April 14, 2026, at 13:00 in the Mercator 12 auditorium (Place Louis Pasteur 3, LLN) to discuss the ongoing research carried out as part of the project. The seminar is open to all without registration.

Reference  

Bottu, C., & Lambin, E. F. (2026). Mismatch between where solar projects are proposed and approved: The case of PV acceptance in the French Alps. Energy Policy, 211, Article 115103. https://doi.org/10.1016/j.enpol.2026.115103 

Article: Emmeline Van den Bosch & Caroline Bottu

Contrary to popular belief, peatlands and blackwater lakes are not simply carbon sinks that store CO₂: they are vectors for the transfer of ancient carbon from peatlands to the atmosphere, with impacts on the regional carbon balance and global climate. 

Scientists from UCLouvain (professor and researcher Kristof Van Oost's team, Earth and Life Institute, School of Geography) and ETH Zurich have recently highlighted a previously unknown phenomenon: in the Congo Basin, certain large lakes located in the heart of tropical peatlands are releasing carbon stored for thousands of years into the atmosphere.

This major discovery, published in the journal Nature Geoscience, highlights the potential vulnerability of one of the planet's largest carbon reservoirs to environmental change.

To conduct this research, the scientists spent six weeks aboard a boat in the Kasai Basin, in the heart of the Congo Basin, collecting samples and observing these ecosystems, which have been little studied to date. 

The peatlands of the Congo Basin, located in the heart of Africa, are one of the world's largest natural carbon reservoirs. Although they cover only a tiny fraction of the Earth's surface, they contain nearly one-third of the carbon stored in tropical peatlands.

This carbon has accumulated over thousands of years in the form of poorly decomposed plant matter trapped in waterlogged soils, which until now were thought to be relatively stable. 

Huge quantities of carbon dating back thousands of years

By analyzing water from Lake Mai-Ndombe, the largest lake in the region, and Lake Tumba, scientists measured the age of dissolved carbon dioxide using isotopic dating techniques.

Their results show that up to 40% of the CO₂ released into the atmosphere comes from ancient peat bogs, some of which are thousands of years old, and not just from recent vegetation.

These observations reveal that lakes act as transfer vectors: they receive ancient carbon from surrounding peatlands and facilitate its release into the atmosphere.

The challenge now is to determine whether this phenomenon corresponds to a natural balance or whether it reflects a gradual weakening of these ecosystems.

Climate change and human activities exacerbate the process

The results also suggest that climate change could exacerbate this process. Longer periods of drought are likely to dry out peatlands, promoting the decomposition of organic matter and the release of CO₂.

Analyses also show that lower water levels promote emissions of methane, a particularly powerful greenhouse gas. 

In addition to these climatic effects, there is growing pressure from human activities. Deforestation, particularly linked to the expansion of agricultural land, disrupts the water cycle and exacerbates the drying up of soils and lakes.

Ultimately, these changes could further accelerate the release of carbon that has been stored for thousands of years.

A better understanding of the Congo Basin

Through this research, UCLouvain confirms its commitment to studying major global environmental issues.

By combining fieldwork in demanding conditions, cutting-edge analysis, and international collaboration, its scientists are contributing to a better understanding of the Congo Basin, a key ecosystem for the planet's climate balance. 

References

Drake, T.W., Hemingway, J.D., Barthel, M. et al. Millennial-aged peat carbon outgassed by large humic lakes in the Congo Basin. Nat. Geosci. (2026). https://doi.org/10.1038/s41561-026-01924-3 

Discover the fascinating complete report “Why does the Kasaï basin matter?”, with numerous explanations and figures, and breathtaking photos. 

This article was originally written in French by the AREC team of UCLouvain. It is available to be read here. 

Photo credits: photographer Matti Barthel, photographer Travis W Drake, and researcher Kristof Van Oost.

Thanks to knowledge sharing and a mathematical model, the discovery of this potential universal limit of -1.3 MPa enriches our knowledge of plants and could well open up new perspectives on how to adapt agriculture to future droughts. 

Plants and soil: a relationship under strain 

Like us, plants sweat. They lose water through tiny holes on the surface of their leaves called stomata. These pores are used to capture CO₂, which plants need to grow. In order to collect this gas, the stomata must open, causing them to lose water.

“This loss may explain why 500 liters of water are needed to produce 1 kg of wheat”, explains Mathieu Javaux, professor at the Faculty of bioscience engineering and researcher at the Earth and Life Institute.

However, this transpiration is not a waste: it circulates sap, allows nutrients to be taken up from the soil, and cools the plant.  

Transpiration also feeds the continental water cycle. In fact, “on a continental scale, transpiration accounts for 60% of total precipitation”, reveals Mathieu Javaux. 

However, the problem is that if the plant loses too much water, it risks dehydration. Hence the initial question: when do stomata close?

In plants, water flows from the roots to the leaves through a network of vessels called xylem. This continuous column is subject to significant tension due to transpiration, as if the plant were sucking water upward through a giant straw.

Regulating this tension remains complex. If it becomes too strong, there is a risk of embolism. Air bubbles can form in the xylem, interrupting the flow of water.

Without water, the plant dries out and eventually dies. This is why regulating this tension is vital and raises a second question: what determines the closing tension of stomata? 

The story of a potential universal limit 

To answer these questions, Mathieu Javaux, Tim Brodribb (University of Tasmania), and Andrea Carminati's team (ETH Zurich) compiled all existing data on tension during stomatal closure. These measurements had been shared by various laboratories on 19 different varieties.

At the same time, a mathematical model was also used to simulate the behavior of water in the soil and the plant.

The result: the threshold of -1.3 megapascals (MPa) emerged as a constant at which stomata begin to close, regardless of plant type.

Why this universal limit? It is no coincidence; it stems from the laws of soil hydraulics: above this tension, extracting water from the soil becomes much less efficient for the plant. 

But then, why are some plants more resistant to drought? 

The threshold of -1.3 MPa marks the beginning of stomatal closure, not their total closure. Indeed, some plants can close their stomata quickly, while others keep them open longer.

Both strategies have their advantages and disadvantages.

On the one hand, closing stomata quickly improves survival in arid conditions, but at the expense of growth.

On the other hand, keeping stomata open longer promotes growth but increases vulnerability to drought.

This explains why some plants lose less water than others and are therefore more resistant to drought.

Other factors also come into play, such as root size, leaf surface area, and resistance to embolism.

These findings were published in January in the international journal Science and are the result of a collaboration between numerous laboratories.

This proves, once again, the importance of knowledge sharing, particularly in the context of climate change. 

Reference

Andrea Carminati et al., Soils drive convergence in the regulation of vascular tension in land plants. Science 391, 476-479 (2026). DOI: 10.1126/science.adx8114

This article was originally written in French by the AREC team of UCLouvain. It is available to be read here.

The theme of the 2026 ceremony was “Enlighten to understand, resist to move forward”, and it honored three personalities whose careers embody intellectual rigor, courage, and commitment: Izzeldin Abuelaish (Palestinian doctor), Olivier Hamant (French biologist), and Salomé Saqué (French journalist).

The Earth and Life Institute was heavily involved this year, as Professor Valentin Couvreur, a researcher at the Institute, hosted Olivier Hamant, alongside Laurence Albert, director of Student Services at UCLouvain Saint-Louis Brussels.

Studying the complexity and resilience of biological systems

Olivier Hamant, 50, is a researcher in biology and biophysics, and director of research at the Institute for Research in Agriculture, Food, and the Environment at the École Normale Supérieure de Lyon.

He seeks to understand how plants use forces to control their development, combining approaches from molecular and cellular biology, mechanics, and modeling.

More broadly, he questions the complexity, resilience, and fragility of biological systems.

Author of several essays, Olivier Hamant studies humanity's relationship with nature: he advocates a model of society inspired by living organisms, guided by the pursuit of robustness rather than performance. 

Watch below the video portrait of Olivier Hamant created by UCLouvain, featuring Valentin Couvreur and Laurence Albert.

A very special and robust class

Numerous activities and meetings were organized throughout the week as part of the Honorary Doctorates program. 

Olivier Hamant gave a class to a full auditorium of bachelor's students in agricultural sciences. 

The session was also open to students from other years and cursus, and to members of the Earth and Life Institute. 

Professors Valentin Couvreur and Pierre Defourny were in charge and facilitated the discussions and numerous questions that the students had prepared for Olivier Hamant. 

Conference: how to build a resilient society

Alongside journalist Salomé Saqué, also among this year's honorary doctors, Olivier Hamant gave a lecture at the UCLouvain Saint-Louis campus in Brussels on the theme of “Resisting and adapting: how to build a resilient society in the face of cascading crises”. 

The lecture was moderated by Xavier Counasse, editor-in-chief of Le Soir.

The conference by Salomé Saqué and Olivier Hamant can be viewed again below. 

A emotional and optimistic ceremony

The highlight of this intense week was the official ceremony for the awarding of Honorary Doctorates by UCLouvain, in Louvain-la-Neuve. 

The ceremony, which took place in the Aula Magna in front of nearly 1000 people, featured particularly emotional and engaging speeches by this year's three honorees and by the rector of UCLouvain, Françoise Smets.

In keeping with the theme of the ceremony, Izzeldin Abuelaish, Salomé Saqué and Olivier Hamant emphasized the importance of resisting violence and hate, and moving toward other narratives, other possibilities for tomorrow's world. 

Through realistic but optimistic speeches, the honorees emphasized the importance of commitment and resistance, as well as solidarity, listening, and nuance. 

The ceremony was punctuated by multiple standing ovations. It then concluded with a reception in honor of the three honorees. 

You can watch the ceremony again in the replay below. 

And much more...

This article focuses on biologist Olivier Hamant, as he was hosted by a researcher from the Institute. 

However, there is also much to say about Izzeldin Abuelaish and Salomé Saqué, the two other honorary doctors awarded this year, and about the program of this very special week for the university. 

We invite you to read this article (in French) for a more complete overview and to discover the full photo album of the ceremony. You can also find here the three video portraits of the honorees and replays of the events. 

En 2026 encore, l'Earth and Life Institute est de la partie et (co-)organise de nombreux ateliers, conférences, débats et visites. Très actifs, de nombreux membres de l'Institut prendront la parole pendant, ou animeront des activités. Elles sont à retrouver ci-dessous. 

Certaines activités sont réservées à un public scolaire, d'autres sont ouvertes à toutes et tous. 

Pour en savoir plus sur le Printemps des Sciences 2026 et sur l'ensemble des activités organisées dans ce cadre, rendez-vous sur le site web du festival.